Pond Boss Magazine
http://www.pondboss.com/images/userfiles/image/20130301193901_6_150by50orangewhyshouldsubscribejpeg.jpg
Advertisment
Newest Members
dlmpsy, Hasan, ElijahElliott, kirkm, 3Ponds
16313 Registered Users
Forum Stats
16313 Members
36 Forums
37289 Topics
508331 Posts

Max Online: 3583 @ 01/15/20 02:21 PM
Top Posters
esshup 24181
ewest 20046
Cecil Baird1 20043
Dave Davidson1 14173
Bill Cody 13099
Who's Online
9 registered (RStringer, wbuffetjr, TGW1, Kris B, Cliff76169, Sunil, Snipe, JIMS SVT, Jeffrey Bandel), 227 Guests and 585 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
#515674 - 01/13/20 06:51 AM How do I only aerate top half of my water column??
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
If I only wanted to aerate the top half of my water column in Winter how would I do that? I would like to"turn off" the bottom of the pond and eliminate or severely limit it's capacity to consume DO. Water is 20' deep at the deepest. Water temp is 33 degrees.

Could I place diffusers in 4' of water and that would do it or would that cold water mix on down to the bottom anyway? Would discs have to be suspended 18" or so below the water surface??

Bill Cody has told me cold water mixes much easier and farther than warm water. MNFish has video of significant water movement under ice 120' away from a single diffuser being pushed by 1.00-1.25 CFM. I will be pushing double or more CFM per disc.

Is it even possible for me to not mix the bottom water?
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515681 - 01/13/20 11:57 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bocomo Offline


Registered: 05/06/12
Posts: 1242
Loc: Boone County, MO (pond)
Man, I sure don't know. But I think the fancy term you're looking for might be "hypolimnetic aeration." I've seen it discussed here before in the context of summer aeration to preserve stratification as a cold refuge for trout. I'm not aware of a consumer-grade application of it, either.

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=508429

Here is a more recent discussion.
_________________________
Our old pond project (updated 4/11/17)
+Donate ('17)

Top
#515690 - 01/13/20 03:43 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Bocomo thanks for the link. Interesting stuff.

I have seen folks trying not to mix all the bottom water in summer to try to leave a cold refuge. I am trying to understand if it would work the same way in the winter. If I keep the diffusers shallow will it leave bottom water unmixed??
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515691 - 01/13/20 03:53 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bocomo Offline


Registered: 05/06/12
Posts: 1242
Loc: Boone County, MO (pond)
Originally Posted By: wbuffetjr
Bocomo thanks for the link. Interesting stuff.

I have seen folks trying not to mix all the bottom water in summer to try to leave a cold refuge. I am trying to understand if it would work the same way in the winter. If I keep the diffusers shallow will it leave bottom water unmixed??



Ah, I think I misread your original post. I think shallow water aeration is what most people do around here to do exactly what you describe. I'm curious to see what a real pro has to say on this.
_________________________
Our old pond project (updated 4/11/17)
+Donate ('17)

Top
#515694 - 01/13/20 04:15 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
I am interested what they have to say too, Bocomo!

I am wondering if shallow aeration will work the same way in the winter as it does in the summer. I THINK maybe the warmer water temps in the summer help to keep the water stratified. I am wondering if it will stratify the same way in the winter with water that is near freezing.

Basically I am pretty certain by keeping my diffusers in deep water all winter I am keeping the bottom of my lake awake and active and it is a huge Oxygen suck. My DO levels plummet rapidly when there is no hole open (that is with clear water and very few fish). I am wondering if I can shut down that O2 consumption by rearranging my diffusers, and if I can, how deep do I run them.
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515698 - 01/13/20 08:55 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
esshup Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 01/26/09
Posts: 24181
Loc: Grovertown, Indiana
For winter aeration, we place a diffuser (or 2 depending on how much open water is needed) NO MORE than 1/4 total pond depth, and close enough to shore that the open water goes to the shore or at least goes to shallow enough water so anything that might go IN the water with the pond frozen can WALK out.

Critters or humans for that matter that have to climb back up on the ice after falling in might not be able to do so and drown.
_________________________
www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).

Top
#515700 - 01/13/20 09:08 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
esshup Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 01/26/09
Posts: 24181
Loc: Grovertown, Indiana
Originally Posted By: wbuffetjr
Bocomo thanks for the link. Interesting stuff.

I have seen folks trying not to mix all the bottom water in summer to try to leave a cold refuge. I am trying to understand if it would work the same way in the winter. If I keep the diffusers shallow will it leave bottom water unmixed??



That is correct, the O2 will transfer a quite a number of feet below where the diffuser is placed, both summer and winter.

I have a client that wanted to keep trout alive all summer long. That's difficult to do without pumping 54F well water into the pond to cool the water down below 70F. It took us 3 years of experimentation, but this last summer he was able to keep Trout alive in his pond without adding much well water - just enough to keep up with evaporation. grin 1/2 acre pond, 25' deep in the deepest part. If I get off my keister this winter and scribble out how it was accomplished, I'll send it in to Bob for a PB Magazine article.


39F water is the densest and sinks to the bottom of the pond. Warmer or colder water than that rises up to the surface. For cool water fish, if the temp drops too much below 39F they are under stress and are easily affected by bacteria infections. Trout can live in colder water, but I'd like to see them in slightly warmer water than 33F-37F water temps. The other critters in the pond will appreciate the warmer winter water temps too.

MNfish knows how I did it if his memory cells are still working.
_________________________
www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).

Top
#515710 - 01/14/20 08:33 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Esshup

Good part is I don't have to worry about things going into the water besides maybe snowshoe hares. All the animals move off the mountain for winter.

So sounds like basically it will work the same as summer aeration. I am still curious on how winter will change things. For example, if in summer a diffuser placed at 4' deep will cause the thremocline to settle in at X feet, where will the thermocline settle in for that exact same setup in winter?? It would have to change it if the water mixes easier and further. I guess it is going to just take more experimentation for me. Bad part is my experiments take one year to complete, see results and try something different.

You are the pro and I am nothing so don't take my disagreements as me thinking I know anything. However, some things just don't match up with what I have seen. I don't think the 33 degree water temps are bad for what lives in my lake at all. This spring and spring 2018 right after ice out we had huge swarms of "millions" of scuds mating all over the edges of the lake. There were so many that my buddy, that's had a cabin up there for 20 years, couldn't even figure out what they were at first. Turned out it was 2 scuds hooked together mating. That's never happened before. We have more fatheads than ever as well. We caught the first fish this year about two weeks after ice out. It went in the lake October 2018 at 6"-8" and was caught June 2019 at ~14"-15". That growth is with the super low water temps, ice cover from late Oct 18 to mid June 2019 and a mid winter measured DO of .07PPM!! . My point is I am not seeing any evidence the 33 degree water temps are hurting anything at all. I actually think it may be helping fish survive water conditions they may not otherwise survive, but that's just a theory.


Edited by wbuffetjr (01/14/20 08:35 AM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515714 - 01/14/20 09:21 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
esshup Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 01/26/09
Posts: 24181
Loc: Grovertown, Indiana
Not disagreeing about water temps for YOUR particular pond, but anybody else reading the post might have problems in the winter if they have any other fish in their pond besides cold water fish (trout) and fatheads and they placed the diffusers in the deepest part of the pond for the winter. Just remember surviving and thriving are 2 different things, I'd love to see what would happen to your hole size if 2 diffusers were placed 10' apart at 4' below the water surface. Also remember your doming problem? If the lower water was warmer than 33F and the pond froze over, would bringing up say 35F water melt the ice any faster than 33F water?

Moving the diffuser heads into shallower water might help you by creating more wave action - you'd get more CFM from the compressor - what is the pressure/cfm curve for your compressor where they are placed now vs. 1/4 to total pond depth?

There is no thermocline in winter.

In the pond where we have Trout surviving all winter and summer, in winter the diffusers are running at 5' and 8' water depth.

_________________________
www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).

Top
#515723 - 01/14/20 12:30 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bill Cody Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 04/18/02
Posts: 13099
Loc: Northwest Ohio - Malinta OH
Winter water temperature measurements in the water column need to be done on larger water bodies than 0.7 to 1 ac with diffuser/s set at 1/4 or less of the water depth. Example 16-18ft deep set diffuser at 3-4ft and measure the water temperatures of the water column in a few remote areas away from the diffuser/s. Diffuser can be set near one end of the pond and measure water temps at other end but still in deep water 10-16ft. What we don't know is how far and deep water currents from a shallow diffuser will mix into the winter ice covered pond. I think it will be several hundred feet or even much more. It does not take much force energy to mix water that has a uniform density. Water is a very unique substance.

In summer this becomes a whole different story because the warm water of 70+F will want to very strongly float on cooler more dense water below. The closer the surface temp water is to the dense thermocline water (uniform), the easier mixing of the two layers can occur. Resistance to mixing strongly increases more and more as the two temperatures diverge. The more surface water warms above 65-70F the stronger the resistance to mixing becomes due to divergence of water densities. Water constantly becomes less dense as it warms.

Natural wind mixing of summer surface water into depths in many ponds generally occurs down to 6ft at least those in the midwest and northern states. But in large 500+ac lakes strong frontal winds can mix water down to maybe 18-20ft according to my measurements. My MS thesis lake in Ontario had an August thermocline at 23-26ft for 2700 surface acres.

Do any members have records of thermocline depth for southern ponds where summer temperatures persist longer as warm water conditions???

Anglers what are you measuring for thermocline depths of ponds or small lakes that you fish??? Let's get and record some natural summer water mixing depths for various sized USA ponds. Amount of direct wind exposure will have a big influence on natural mixing depth of ponds and small lakes. Ponds smaller than 1 acre in my NW Ohio area rarely mix deeper than 6 maybe 7ft in the larger ponds. This depth is where the natural thermocline generally starts. In sheltered clam water ponds the thermocline could commonly be as shallow as 4-5ft??


Edited by Bill Cody (01/14/20 04:34 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515746 - 01/15/20 09:46 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
TGW1 Online   content


Registered: 09/19/14
Posts: 2991
Loc: Harrison Co. Texas
Bill, here in NE Tx (I 20 corridor) I think the thermocline depths depends on the waters depths and fertility. In my pond (3 acres) with the deepest being 11 to 12' I see it at or around 7' but I have surveyed Highflyers lake (guessing 20 acres) and using a depth finder, and we saw it @ or around 12 to 14'. I think he has 25' water depths. At the lakes like lake Fork it will or may hang around 20' during the long summer months.


Edited by TGW1 (01/15/20 09:50 AM)
_________________________
Do not judge me by the politicians in my City, State or Federal Government.


Tracy

Top
#515748 - 01/15/20 11:19 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bill Cody Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 04/18/02
Posts: 13099
Loc: Northwest Ohio - Malinta OH
TGW1 - I think Highflyer aerates his pond and when the water is aerated the thermocline is non-existant or atypical compared to non-aerated water. I am suggesting that we get thermocline depth for non-aerated waters.


Edited by Bill Cody (01/15/20 11:20 AM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515751 - 01/15/20 12:58 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Bill I am actually fairly certain Brian is NOT aerating his lake. He has been talking about installing aeration, but as far as I know he hasn't installed it yet.

I would like to propose an idea and hear theories on what y'all think the results would be.

What if I took a diffuser disc pushing 2 CFM and in 10' of water I suspended the disc ~18" under the waters surface. Once ice formed and assuming I kept a hole open, how far down the water column would the DO reach??

Would the colder water, that had been exposed to air, float on top of what should be the 39 degree water on the bottom?

If this would work, I could get even more air out of my pump while simultaneously drawing less power! That would be a huge win alone. If it would also keep my bacteria from consuming all my DO then it's a grand slam.


Edited by wbuffetjr (01/15/20 01:20 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515752 - 01/15/20 01:45 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Quarter Acre Offline


Registered: 06/10/16
Posts: 1635
Loc: West Central Missouri
I know of no studies regarding aeration/thermoclines to cite here, so I can only throw SWAGs around.

I think 2 CFM through a decent diffuser would draw at least some of the waters up from the 10 foot depth mixing this 39 degree water with the surface waters. The way I think about it is that the diffuser is acting like a pump (about 700 to 1000 gpm for discussion) moving the water upward. The water going upward has to go somewhere and, for the most part, it goes outward along the water's surface (it cannot go directly back down against the upward current). The water going upward has to come from somewhere and that is from below. Most is from directly below, but there are no strong confines to keep it from drawing up some from the depths. Some will be drawn from the bottom. The unknown is how much. Now, set the diffuser 18" down with a large plate a foot or so below it and you have created a confine that keeps any water from being drawn upward from down deep. Water goes up and meets the water/air interface, spreads out along the surface, but must be drawn back from the sides at a shallower depth. This creates a micro boil, if you will, that stays up in the water column.

Would something like this server your purpose?

If you do not restrict the available water flow from beneath, I fear, that you will affect the thermocline to at least some degree.

I also think using multiple diffusers spread out with a lot less air throughput could better suit you purpose. Less air per diffuser means less "pump" power, means less water movement, which means it's less likely to draw water up from deeper depths. This could also be done by moving the diffuser closer to the surface, but it's less efficient than spreading that air out over multiple heads.

Bottom line is that I think 1 diffuser at full throttle will move water up from 10 foot deep. Key word is "think".
_________________________
Fish on!,
Noel

Top
#515765 - 01/16/20 07:36 AM Re: How do I only aerate top half of my water column?? [Re: Bill Cody]
TGW1 Online   content


Registered: 09/19/14
Posts: 2991
Loc: Harrison Co. Texas
Originally Posted By: Bill Cody
TGW1 - I think Highflyer aerates his pond and when the water is aerated the thermocline is non-existant or atypical compared to non-aerated water. I am suggesting that we get thermocline depth for non-aerated waters.


Bill, Brian was not set up for aeration at that time. He told me he had plans to aerate in the future. And my pond was checked before I started up my diffusers.
_________________________
Do not judge me by the politicians in my City, State or Federal Government.


Tracy

Top
#515766 - 01/16/20 08:20 AM Re: How do I only aerate top half of my water column?? [Re: Quarter Acre]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Originally Posted By: Quarter Acre
I know of no studies regarding aeration/thermoclines to cite here, so I can only throw SWAGs around.

I think 2 CFM through a decent diffuser would draw at least some of the waters up from the 10 foot depth mixing this 39 degree water with the surface waters. The way I think about it is that the diffuser is acting like a pump (about 700 to 1000 gpm for discussion) moving the water upward. The water going upward has to go somewhere and, for the most part, it goes outward along the water's surface (it cannot go directly back down against the upward current). The water going upward has to come from somewhere and that is from below. Most is from directly below, but there are no strong confines to keep it from drawing up some from the depths. Some will be drawn from the bottom. The unknown is how much. Now, set the diffuser 18" down with a large plate a foot or so below it and you have created a confine that keeps any water from being drawn upward from down deep. Water goes up and meets the water/air interface, spreads out along the surface, but must be drawn back from the sides at a shallower depth. This creates a micro boil, if you will, that stays up in the water column.

Would something like this server your purpose?

If you do not restrict the available water flow from beneath, I fear, that you will affect the thermocline to at least some degree.

I also think using multiple diffusers spread out with a lot less air throughput could better suit you purpose. Less air per diffuser means less "pump" power, means less water movement, which means it's less likely to draw water up from deeper depths. This could also be done by moving the diffuser closer to the surface, but it's less efficient than spreading that air out over multiple heads.

Bottom line is that I think 1 diffuser at full throttle will move water up from 10 foot deep. Key word is "think".


QA thanks for the input.

I have been trying the multiple diffusers spread out and I am now leaning towards more air concentrated in one or possibly two very shallow spots. At two feet I will have 9.9 CFM to work with (after 10,000' compressor de-rate). I think it boils down to this, I need plume intensity to get through heavy ice and snow. That Trumps everything. So I THINK my "baseline" when configuring the layout has to start with less stations and more CFM per station than would be optimum for summer aeration. Same as you, keyword is "THINK"

I am considering one 4 head station pushing ~8 CFM and one single head station pushing ~1.9CFM, both as close to same depth as possible ~2-3'. I will just have to adjust valves to make the plumes look appropriate. Maybe come up with a plate to block water draw from bottom. The only reason for the second station is redundancy. I am still gun shy about a line freezing up and a second station at least gives me an option. Otherwise I think we would go all in on one spot.

Hopefully a setup like this would allow a bottom layer of cold water.


Edited by wbuffetjr (01/16/20 08:21 AM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515768 - 01/16/20 09:33 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
TGW1 Online   content


Registered: 09/19/14
Posts: 2991
Loc: Harrison Co. Texas
What about running a deicer from Kasco? Advertisement show 50' open water. Running it along with your diffuser system. I read where Cecil Beard 1 ran a surface aeration volcano with his pond having 13 to 18" of ice. It's an old post and have not seen him active here for a couple of years.
_________________________
Do not judge me by the politicians in my City, State or Federal Government.


Tracy

Top
#515770 - 01/16/20 10:34 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
highflyer Offline


Registered: 07/09/11
Posts: 1938
Loc: East Texas
Bill,
I have aerated my brood ponds several times in the past and have that data available. In short, I can turn them over in 20 minutes using Kasko's 12V DC aerator. I have tested a 3/4 HP aerator in the big pond as well and the area it oxygenates is substantial in 13 feet of water during the hottest part of the summer. I believe it is due to the power of the plume that it is able to draw bottom water up. If I had used a smaller pump, I do not know if I could influence the bottom of the pond during the hottest parts of the summer. I am willing to set up that aerator again and test it in different depths of water if you could use the data.

About my thermocline, I have gathered data every year and when the big pond started, I had a thermocline around 11 feet. The pond was only half full when I got my meter. As the pond filled the thermocline remained around 12 feet. As the trees in the north end (shallow end) started to rot away and allowed for more wind action on the pond. I have seen the thermocline closer to 14 feet until August when the winds drop substantially. Then in August, I see the thermocline back at 11-12 feet (nine feet was the worst I have ever seen and that was very short lived). As soon as the winds pick back up in Sept, the thermocline will drop to 14 feet again until the water temps drop an we have more mixing for the winter.

I am trying to setup a small aeration system in the deep end of the pond to raise cold stagnant water from the bottom during the summer months to cool the top water and lower the thermocline. This system will be solar and wind powered. The trick is to have enough power available to run 24/7 (think large batteries for the 8-10 amp draw). With any luck, this season will be the one that sees this project running. More data will follow.
_________________________
Brian

The one thing is the one thing
A dry fly catches no fish
Try not to be THAT 10%

Top
#515771 - 01/16/20 10:41 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bill Cody Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 04/18/02
Posts: 13099
Loc: Northwest Ohio - Malinta OH
I don't think a kasko surface diffuser would work for the winter conditions of 10,000ft elevation especially when no one is continually present to monitor the ice buildup. Winter, snow, and temps are too harsh. I think a huge frozen fountain would be the result. I have pictures of what 0F temps do to fountains making them into solid ice sculptures.

I think Quarteracre has fairly accurately envisioned what will happen when the membrane diffusers are placed at 18"-2ft below the surface. He says ""The water going upward has to come from somewhere and that is from below. Most is from directly below, but there are no strong confines to keep it from drawing up some from the depths."" Yes I think there are no strong flow restrictions due to large differences of water density at temps of 34-40F compared to summer water densities of 55F and 80+F. Water at 34F-40F flows and mixes very freely. I think someone needs to do some practical research like this to find out what does actually happen during ice cover.

I am not sure how well or effective the lower deflector plate will cause the desired results. Unless someone has direct experience with something like this all is speculation until someone actually tests the theories.


Edited by Bill Cody (01/16/20 10:43 AM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515772 - 01/16/20 10:50 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bill Cody Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 04/18/02
Posts: 13099
Loc: Northwest Ohio - Malinta OH
Highflyer very good information about thermocline depth in Texas. We need more information from others like this. Now for reference, the pond with a summer thermocline usually at 11-12ft has how big of surface area?

Highflyer says his large pond is 14 acres. Average depth of the shallow end is around 3-4 feet. The middle of the pond is a very lazy V bottom. The average depth is around 8 feet with a substantial channel towards the east side. The deep end is at the dam. The average depth of the deeper water is around 18 feet but there is an "J" of deeper water in front of the dam.


Edited by Bill Cody (01/16/20 09:42 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515776 - 01/16/20 11:47 AM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
MNFISH2 Offline


Registered: 06/06/16
Posts: 104
Loc: MINNESOTA
I shot this short video a couple of years ago while ice fishing one of my ponds.

- 1/3 acre surface area with a max water depth of 6'.
- Single membrane diffuser positioned in 4' of water
- 1 cfm output from a direct drive solar aerator.
- camera was set in 6' of water about 120' away from the diffuser

I was very surprised to see how much the water circulated!

https://youtu.be/K98EfJojsTw

Top
#515777 - 01/16/20 01:09 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Does anyone know how deep a vertex diffuser can pull water from? Can it pull water up 5'? 10'? That would be very interesting to know.

Also, if I am trying to keep and hole open, but not disturb the bottom layer of water, what would happen if I turned the diffuser discs upside down and had them pointing towards the bottom of the pond? We should get the surface agitation to open a hole but not move water near as far right??? What if I turned the disc 90 degrees to the water??


What would this open hole, with little water movement, do for DO levels??


Edited by wbuffetjr (01/16/20 01:27 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515778 - 01/16/20 01:43 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Bill Cody Offline
Moderator
Ambassador
Field Correspondent

Lunker

Registered: 04/18/02
Posts: 13099
Loc: Northwest Ohio - Malinta OH
I think how deep the Vertex diffuser can pull water will have a lot to do with the temperature profile of the water column. The more divergence of the top and bottom the less distance below the diffuser that it can pull water.

As far as diffuser orientation, I think relates back to a prior comment by esshup. ""Moving the diffuser heads into shallower water might help you by creating more wave action - you'd get more CFM from the compressor...."". When esshup and I were experimenting with this topic for our article in PBoss magazine about winter aeration, I discovered that creating larger bubbles caused more surface wave action. This greater wave action caused the open ice hole to be larger than an upwelling that originated from small bubbles deeper in the water column. I am also guessing this probably caused less deep water circulation. I created larger bubbles by using a single 9" ceramic air stone and also by not having a diffuser or a coarse bubble diffuser on the end of the hose. Experiment with these two ideas and they will give you a better idea of "surface wave action" and deep water mixing.


Edited by Bill Cody (01/16/20 01:46 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515780 - 01/16/20 01:57 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
wbuffetjr Online   content


Registered: 08/16/14
Posts: 1100
Loc: in the mountains
Bill I am not the best writer so hard for me to get exactly what I am thinking into words.

I feel pretty confident that we can get an open hole now that I understand the true problem which is doming.

My next problem is this (I THINK): how do I get an open hole without moving SO much water that I mix the bottom layer of water which I think is keeping the bacteria active and consuming DO. I would like to oxygenate the top of the water column and sacrifice the lower water. Let it go anoxic and hopefully shut the bacteria down.

FOR EXAMPLE:

I THINK if I place a diffuser on the bottom of the lake in 4' of water I am going to continue feeding O2 to the soil water interface/bacteria and I will be fighting that bacterias' O2 consumption all winter.

I THINK if I suspended a diffuser station some shallow depth below the waters surface (3', 4', etc) over 20' deep water, I could keep a hole open, oxygenate the water BUT not provide oxygen to the soil water interface. In theory I THINK that should choke out the bacteria and put a stop to the majority of my BOD???

Thoughts?


Edited by wbuffetjr (01/16/20 02:12 PM)
_________________________
Keep This Forum Viable, Read Pond Boss Magazine -
America's Journal of Pond Management

Top
#515781 - 01/16/20 02:46 PM Re: How do I only aerate top half of my water column?? [Re: wbuffetjr]
Quarter Acre Offline


Registered: 06/10/16
Posts: 1635
Loc: West Central Missouri
I think your "THINKS" are accurate, but I still worry about pulling up water from the 20' depths. I know thermoclines will resist water moving from one side to the other, but that confine has got to be weak compared to several hundred gallons per minute of flow in such an open environment. I'd love to see a study that shows the strength of the thermoclines!

Here's an idea to consider (see photo). It is based off of the simple under-gravel filters you see in fish aquariums that are powered by air stones. The overall lengths of the tubes would have to be guessed at, but would not be too critical so long as the inlet is far from the bottom of the BOW. And, the tube diameter, compared to the diffuser diameter would have to be taken into consideration. If using a 12" diameter diffuser, a 20 inch diameter tube would be my guess. The larger the better, but 20 inches would allow for alot of water to be drawn past the diffuser (the diffusser acts like a plug if the tube gets too small an water flow gets choked off). Is this practical for you? I am PRETTY SURE this would greatly reduce the amout of deep water being drawn up to the surface...



EDIT: Something similar could be done using a couple 55 gallon drums with the diffuser centered in two stacked barrels (top barrel without top or bottom, bottom barrel without it's top and holes cut around it's lower perimeter). The J-Tube would be better because it draws it's intake water from above, whereas the barrel rig would draw water from it's lower sides.


Attachments
J Tube.jpg (60 downloads)



Edited by Quarter Acre (01/16/20 02:55 PM)
_________________________
Fish on!,
Noel

Top
Page 1 of 2 1 2 >

Today's Birthdays
jimmy s.
Recent Posts
res how far north?
by Snipe
Today at 11:10 AM
New Column in Pond Boss
by RStringer
Today at 09:33 AM
8 acre pond at 10,000' - lots of aeration ?s
by Bill D.
Today at 09:18 AM
Project de-ice the pier
by Mfitzs70
Today at 05:04 AM
Aerator - what size and how many lines?
by TucknDucks
Today at 01:54 AM
Finally pulled the trigger!
by teehjaeh57
Today at 01:38 AM
Water Temp is 59, keep aerateing?
by Mike Whatley
Yesterday at 08:19 PM
Weird copper discoloration
by BrianL
Yesterday at 05:51 PM
Wannabe Lake
by BrianL
Yesterday at 11:14 AM
Pond Porn
by gehajake
Yesterday at 10:44 AM
Newly Uploaded Images
Getting photos on this forum is a PITA!
Retreat
I Subscribe Permanent Link
Need Plants Identified - Texas Pond - Lily Pad ...
Personal Record BGxRES
Harry's Pond

2014 POND BOSS INC. all rights reserved USA and Worldwide