Pond Boss
Posted By: Sk187 Aerate in the day or at night? - 07/07/16 11:34 PM
I have been running my 5 diffusers 24/7 and its costing about $150 per month and I would like to cut that in half.

I see lots of people are running 12 hour cycles and was wondering if the 12 hours should be during the hot day or cool night?

Thanks!
Posted By: canyoncreek Re: Aerate in the day or at night? - 07/08/16 12:30 AM
SK187... I'll try to answer. First for a pond that has exposure to wind and is 10 feet deep or less the aeration may not be necessary at all. There is not much temperature stratification or a thermocline and no large zone of low oxygen water. Steady wind on top adds oxygen and the main advantage of aeration would be to set up a current of water from bottom to top to improve possibility of muck getting some moving water and air to it. It also will tend to even out the temperature from top to bottom to SOME degree. You always will have warm at top and colder at the bottom.

The need for aeration to prevent fish kill is more a problem with deeper ponds or ponds that have heavy vegetation with heavy oxygen consumption (when the vegetation dies or consumes oxygen suddenly, or with temperature changes, rainfall events etc).

I have a single aerator and feel that it probably makes me feel better (more than making the pond a better place) in that I'm trying to keep things moving at the bottom. I have heavy leaf falls in the fall and I try not to let the dead leaves stagnate too much and build up on the bottom. I'm sure the smaller critters and minnows love riding up the column of bubbles too.

In general, probably moving water is always better than still water.

I use winter time to ice skate on the pond so I don't run aerator in the winter at all. Many move at least one of their deep aerators to the shallows in winter to prevent winter kill.

The experts here could tell you if you truly need 5 aerators or not. I don't recall any other recently active poster on this forum using 5 diffusers and some have pretty big ponds.

You probably could get by with 1 or 2 diffusers in the deepest points of the pond and with proper spacing to help cover the area better.

I personally start running the diffuser when the air gets warm and muggy in June and I run it at night to try to keep water temps cool. Cooler temps means happier fish and less plant/algae growth.

On years that I have tilapia in the pond I switch to daytime use in the early fall and until the tilapia die to try to mix that cold bottom water with the day time sun to keep it warm just a bit longer for tilapia to survive and eat more FA.

Generally people struggle more with too hot of pond water than the opposite.

I'll admit, it sounds strange but when we have bad ice conditions in the winter and have a thin skin of ice with wet snow on it and the skating looks like it is going to go south for a while, I have cranked up the aerator to try to melt the thin skin of ice and slush and hope the weather will allow for precipitation free cold to come and get a good ice base again smile

Posted By: NEDOC Re: Aerate in the day or at night? - 07/08/16 12:31 AM
I go cool of night in hopes of keeping my water temps down.
Posted By: Shorty Re: Aerate in the day or at night? - 07/08/16 02:10 AM
I think you would be fine aerating just at night, I would consider running it during the day only when a strong cold front comes through.
Posted By: Sk187 Re: Aerate in the day or at night? - 07/08/16 02:10 AM
Originally Posted By: canyoncreek
SK187... I'll try to answer. First for a pond that has exposure to wind and is 10 feet deep or less the aeration may not be necessary at all. There is not much temperature stratification or a thermocline and no large zone of low oxygen water. Steady wind on top adds oxygen and the main advantage of aeration would be to set up a current of water from bottom to top to improve possibility of muck getting some moving water and air to it. It also will tend to even out the temperature from top to bottom to SOME degree. You always will have warm at top and colder at the bottom.

The need for aeration to prevent fish kill is more a problem with deeper ponds or ponds that have heavy vegetation with heavy oxygen consumption (when the vegetation dies or consumes oxygen suddenly, or with temperature changes, rainfall events etc).

I have a single aerator and feel that it probably makes me feel better (more than making the pond a better place) in that I'm trying to keep things moving at the bottom. I have heavy leaf falls in the fall and I try not to let the dead leaves stagnate too much and build up on the bottom. I'm sure the smaller critters and minnows love riding up the column of bubbles too.

In general, probably moving water is always better than still water.

I use winter time to ice skate on the pond so I don't run aerator in the winter at all. Many move at least one of their deep aerators to the shallows in winter to prevent winter kill.

The experts here could tell you if you truly need 5 aerators or not. I don't recall any other recently active poster on this forum using 5 diffusers and some have pretty big ponds.

You probably could get by with 1 or 2 diffusers in the deepest points of the pond and with proper spacing to help cover the area better.

I personally start running the diffuser when the air gets warm and muggy in June and I run it at night to try to keep water temps cool. Cooler temps means happier fish and less plant/algae growth.

On years that I have tilapia in the pond I switch to daytime use in the early fall and until the tilapia die to try to mix that cold bottom water with the day time sun to keep it warm just a bit longer for tilapia to survive and eat more FA.

Generally people struggle more with too hot of pond water than the opposite.

I'll admit, it sounds strange but when we have bad ice conditions in the winter and have a thin skin of ice with wet snow on it and the skating looks like it is going to go south for a while, I have cranked up the aerator to try to melt the thin skin of ice and slush and hope the weather will allow for precipitation free cold to come and get a good ice base again smile



Thanks for the detailed reply.

My pond is a little less than 2 acres, originally 10 feet at the deepest but over the years has filled in a lot with muck.

The diffusers were professionally installed about 15 years ago by a pond management company. I was not the owner at the time but can only assume they used that many for a reason.

I think the reason for 5 is the odd shape of the pond (lots of little pockets).

One diffuser or 5 doesn't really matter as they all run off the same 1.25hp pump and are all already installed.

I have never really had any fish kill issues, just lots of weeds and FA.

I finally nuked the pond with fluridone 2 weeks ago and it is looking great.

Guess I really dont even know if I need them but seems a shame not to run a perfectly working expensive system.
Posted By: Sk187 Re: Aerate in the day or at night? - 07/08/16 02:13 AM
Originally Posted By: NEDOC
I go cool of night in hopes of keeping my water temps down.


I was thinking the opposite, pump the cold water from the bottom up during the day when temperature outside is 90+.

At night the surface water cools down significantly, right?
Posted By: canyoncreek Re: Aerate in the day or at night? - 07/08/16 02:27 AM
If you want to heat your water up, yes, then pump daytime so that nice cool water that carries more dissolved oxygen can heat up. This will add stress to fish, and will dump some of the dissolved oxygen out to the air as hot water can't carry as much.

Run it at night and you mix the pot, bring cool air to surface but the heat transfer from air to that circulating water will be less and if it is cool enough out (say 68 or less) even the water on the bottom in mid summer may cool a bit as it dumps heat to the air.
Posted By: highflyer Re: Aerate in the day or at night? - 07/08/16 02:43 AM
SK,

You are using bottom diffused aeration. The number one reason it is used is to turn the pond over at least one time a day. This get oxygenated water the bottom of the body of water. This opens up additional waters for your fish to live in and aids bacteria to reduce the muck on the bottom.

SO,

How long does your system need to run to turn your water over at least one time per day? That is the shortest time you should run your system daily. It is not about money saved if you kill your fish and disrupt your biology.

With all that said, I would bet if you talked to an expert (like from vertex), they can tell you your expected turnover rate. Then you can see if you want to cut back on your aeration without sacrificing your fish and biology.
Posted By: Sk187 Re: Aerate in the day or at night? - 07/08/16 03:15 AM
Thanks for all the replies, I am just trying to figure out what I need I suppose.

The system was off for about 6 years and I just turned it back on last year when I took ownership of the house from my mother.

The bass and bluegill seemed just fine with the aerators off all those years.

I remember a few dead fish over the years but no big fish kills.

As far as I know the aerators were installed to reduce muck and weed growth.

May have just been a good aerator salesman also.

Is 24/7 aeration the best bet?
Posted By: Bill D. Re: Aerate in the day or at night? - 07/08/16 12:05 PM
FWIW I aerate from midnight to a hour or so after dawn. My understanding is this time period is when fish kills can occur as the vegetation is not producing O2 (actually using it) and DO can drop to dangerous levels. As Highflyer stated, a rule of thumb is the aeration should be run long enough to turn all the water in the pond at least once in 24 hours.
Posted By: NEDOC Re: Aerate in the day or at night? - 07/08/16 02:33 PM
Originally Posted By: Sk187
Originally Posted By: NEDOC
I go cool of night in hopes of keeping my water temps down.


I was thinking the opposite, pump the cold water from the bottom up during the day when temperature outside is 90+.

At night the surface water cools down significantly, right?


If temps are between 45 and 70 during the day I will run my during the day, and usually 24/7. But if high temps are over 80 I will only run at night as I don't want to warm my water. The warmer your water the less DO it can hold.
Posted By: RC51 Re: Aerate in the day or at night? - 07/08/16 03:17 PM
SK,

I run my air at night only and been doing it ever sense I had my pond 6 years ago.

If you had to choose between night or day to run your air. Night is your answer IMO. Like said above all the weeds and FA in your pond will be taking D.O. from you all night long until the sun comes up. So running it at night helps with that!

There are several reason why you run air. Not just for D.O. that is the main one I spose but there are other reasons.

1 other reason is for just good old pond health. I believe air in your pond if done right can make / improve your pond overall health which improves your fish overall health. After all they are living in it.

Would you like to live in a home that you could never get out of and never have any fresh air or a breeze or clean oxygen? I know I wouldn't!! smile

I am floored by your electric bill? Wow I run my pump 10 or so hours a night and my bill is like 11 bucks for the month... I may have to give up air if my bill was as high as yours.... lol

RC
Anyhow like I said if you have to choose one run it at night. I have mine on a timer that runs from Dusk till Dawn it works great!

RC
Posted By: sprkplug Re: Aerate in the day or at night? - 07/08/16 03:47 PM
I've experimented with several configurations, but have always come back to 24/7.
Posted By: canyoncreek Re: Aerate in the day or at night? - 07/08/16 04:37 PM
SK, get a Kill-o-watt meter and plug your aerator compressor into it. That will tell you the use of the aerator system only and give you a more accurate idea of what your true electric costs are to run it.

Sue at Vertex (advertiser contributer to this board) can run calculations on your pond size and turn over recommendations. My guess is that in 24 hours about 2-3 heads would still turn it over in 24 hours but don't know all the details of depth and the shape of your pond.
Posted By: Bob Lewis Re: Aerate in the day or at night? - 07/10/16 03:33 AM
Who sells the best fountain aerator ?
Posted By: Shorty Re: Aerate in the day or at night? - 07/10/16 03:50 PM
Originally Posted By: sprkplug
I've experimented with several configurations, but have always come back to 24/7.


Reason?
Posted By: DrLuke Re: Aerate in the day or at night? - 07/10/16 05:46 PM
So after reading all of the above, now I'm worried I should be shutting down my air during the day. Our air was put in April 14th, new, and been running 24/7 ever since. If I have it off for the daylight hours, how fast will it stratify? 2.5 acre pond, ave 8 feet deep. I have been hoping to help 'activate' the aerobic bacteria on the bottom, to begin 'de-euthrifying' my pond over the next few years, so I thought the warmer water temps plus oxygen would help this. Am I doing more harm than good with mixing that warm summer water with the cool water on the bottom??
Posted By: snrub Re: Aerate in the day or at night? - 07/10/16 06:29 PM
Sk187 I do not have an answer for you and am interested in the answers you are getting as much as you are.

But one suggestion or at least question I would raise is the possibility of using a different pump. Could it be possible you could use a lower capacity pump (for example a half or 3/4 horsepower pump), cut your electricity bill enough to pay for the pump in a matter of reasonable time, and run the pump longer hours.

I don't know. Not even suggesting it. Simply raising the question of running a smaller pump continuously or a large pump for only a few hours.

In other words would running your big pump for say 4 hours per day be preferable or running a smaller pump 24-7 (with resulting similar electric costs)? I don't know and will be interested to hear the answers of those that do.
Posted By: sprkplug Re: Aerate in the day or at night? - 07/10/16 09:30 PM
Originally Posted By: Shorty
Originally Posted By: sprkplug
I've experimented with several configurations, but have always come back to 24/7.


Reason?


Consistency and visual verification. I'm not normally there from 9 pm until 8 am.....how would I know it was working if I had it on a timer for evening operation only? I feed of an evening, well before the "on" time I had set when I used a timer. It would be the weekend before I realized it had quit working. That actually happened once. Not good during the hot, windless, dog days of summer.

If I had a species that needed cooler water it might be different however. But the BG, HBG, LMB scenario hasn't presented me with any issues due to hot water.
Posted By: Shorty Re: Aerate in the day or at night? - 07/10/16 11:24 PM
Thanks Tony! I am still trying to figure out the best way to aerate my pond with YP and SMB present. Aerating 24/7 is likely hard on my YP due to warmer water temps. My SMB don't seem to be very low DO tolerant so I am not sure if areating just at night will be sufficient given the heavy algae blooms I have had this summer. Twice so far this summer I have lost a small number of my larger SMB when a rapid temperature change caused the bloom to die back significantly while the aeration was shut off during the day. I think I will aerate from 7PM to 7AM and turn it on full time only when the weather forecast calls for it. I'll be able to make sure that it is running when I go out to feed after 7PM.
Posted By: sprkplug Re: Aerate in the day or at night? - 07/11/16 12:46 AM
Sounds like a plan, Steve....sorry to hear about those smallies!
Posted By: Rainman Re: Aerate in the day or at night? - 07/11/16 01:41 PM
Originally Posted By: Bob Lewis
Who sells the best fountain aerator ?


Welcome Bob! Several vendors listed in PondBoss Resources on the home page sell fountains, and aerators. Fountains can be pretty, yet do almost nothing in the way of aeration. Aerators come in a few forms, but I can't think of a single one I'd call a fountain, or "pretty"....

What are your goal and pond shape/size?
Posted By: Shorty Re: Aerate in the day or at night? - 07/11/16 01:42 PM
I still have some nice smallies present, I caught a 17"er a few nights ago and had a big one throw the hook last night. I am going to add a few HSB this fall just to make sure I am not short on predators.

Here is a picture of two low DO stressed smallies, this was the day after a very strong cold front with rain that came through, my water went from very green to brown during the previous day. Secchi dish readings went from 9" to 14" in a short amount of time. I am pretty sure the lighter colored one on the left was one of the ones that didn't make. I had a dozen SMB behaving like this the day after the front came through and I know that eight of those didn't make it.

Posted By: Rainman Re: Aerate in the day or at night? - 07/11/16 01:44 PM
Shorty, IME, YP are pretty heat tolerant as long as DO is good.

I know a few ponds well south of your clime with YP, WE, and SMB where the water at depth pushes 85 in the heart of summer with no issues at all as far as mortality.

I have shipped several YP to all of Florida and parts of AZ that are stocked into unaerated ponds and those are reported as "doing well".

If low DO problems have occurred, I would suggest aerating 24/7 and possibly get a surface agitation backup if needed, whether it be a Kasco or even a boat motor....
Posted By: Shorty Re: Aerate in the day or at night? - 07/11/16 01:56 PM
I think my issue is the heat, very green water, and very sudden changes in the weather with big temperature swings. My water was 85 degree last night and it will get hotter. I have been running my aerator 24/7 since the last cold front came through but I am going to dial it back today.
Posted By: RC51 Re: Aerate in the day or at night? - 07/11/16 04:48 PM
Yeah my water here gets hot also! Real hot. I only run my air from dusk till dawn, I have LMB, HSB, BG, RES and I have never had an issue yet...

I think the problem with your SMB is yes they can tolerate higher temps but as soon as a little something goes wrong in your pond.... then their in trouble... As long as the status quo stays the same then they can be ok.... They are a bit more touchy of a fish kinda like trout but not quite as bad...

RC
Posted By: DonoBBD Re: Aerate in the day or at night? - 07/11/16 05:42 PM
I have been extremely pleased with Bill Codys recommendations on running my aeration in our YP pond. He recommended running the air at night from 1am to 7am only. This has cut the evaporation down in half. The top 28-36"s will warm during the day and the small minnows love the warm water. If we go for a swim our toes around 48-60"s down will get numb from how cold the water is.

We run our water fall at night too now. When the pond had ice and was cold we run the air in the day and waterfall to bring the water temp up. Once the water was at 60 we turned it into night mode. This helped us get our perch feeding quick in the spring and they keep feeding in the summer because the water is not too hot.

Perch seem like they just disappear when the water got over 75. I don't know why but they just stop eating. This year running only at night the perch are eating three times as much feed as they did last year. They are eating in July now still like its May. Last year running the air 24/7 the water hit 85 and I really thought the perch were gone from our pond. For two months they stopped eating. The aeration run in the day pushed our water temp up to 85 from top to bottom.

Running at night we have been able to keep the pond below four feet under 75 all year so far. Swimming is still nice because the top 30"s still warms in the hot day time. The volume of water that is colder far out weighs the volume that warms.
Posted By: NEDOC Re: Aerate in the day or at night? - 07/11/16 07:07 PM
That's interesting. Wish I kept track of my water temps better. Thanks for posting that.
Posted By: snrub Re: Aerate in the day or at night? - 07/13/16 12:28 PM
This is an interesting subject. Having read the thread it made sense to me from an evaporation point and water temperature point to run the diffusers only at night.

I have always (for the last two years) run 24/7 but after reading this thread put two of the three diffusers on a timer the other day and only run the two from midnight to 7am and let the third continue to run 24/7 (I have 3 seperate pumps that each run an individual diffuser so it is easy for me to selectively run each one).

Then the more I thought about it, this morning went out and took the timer off and am going to run 24/7 on all 3 again.

Here are the things I thought about (sometimes thinking gets me into trouble crazy ). If lower anoxic water is being transferred from the lower portion of the pond AND at night the algae are not creating DO in the upper water would I only be pushing low DO water up to mix with water already getting lower in DO? Would I not be mixing low DO water back down to the lower water?

It seems to me a person needs to take high DO water created in the upper few feet of water by daytime algae and mix it with lower water to create a DO "sink" as storage so that at night this lower water is already charged with DO.

On the other hand, this may have more to do with water movement capacity. With a large enough pump so the BOW can be turned over multiple times a day, perhaps it only needs to run a few hours for the full turnover. I don't think I have that much capacity.

So now basically by using what I think is a logical argument I am running the pump in the day time to move high DO water to the lower regions of the pond to be used at night. Have I just confused myself more than I already was?
Posted By: RC51 Re: Aerate in the day or at night? - 07/13/16 01:25 PM
I think your kinda right snrub that's why most folks would say running your system 24/7 is best.... but if you HAVE to choose one day or night then night is the preferred option do to the plants and FA not producing D.O. at night. I have never ran mine during the day and I been fine but my pond is only 9 feet deep. So I am not at as much risk as say someone who has a pond 15 feet or deeper...

RC
Posted By: DonoBBD Re: Aerate in the day or at night? - 07/13/16 01:57 PM
What we found was that running 24/7 was we had bubbles on our rocks around the whole pond on the shore. The water temp would work its way up to the mid 80's for two months with this temp top to bottom.

Running at night we do not have the over oxygenated water with bubbles on the rocks and much cooler water temps over all.

Our fish are Yellow perch and will turn off the feed when the water temp gets over 75 so for us running at night is best for us. Until I seen it first hand I would have never thought we could heat the pond top to bottom with aeration.

Cheers Don.
Posted By: RC51 Re: Aerate in the day or at night? - 07/13/16 02:44 PM
So once again what your saying is "It All Depends" smile On you giving situation with what you have in your pond fish wise.

A temp of 80 all through out my pond would be ok with the type of fish I have LMB/BG/RES/HSB... but if you had trout or maybe SMB that would prefer cooler water then running your air 24/7 may not be a good thing to do in the heat of the summer...

RC
Posted By: Shorty Re: Aerate in the day or at night? - 07/13/16 04:17 PM
SMB are OK with warmer water, they just have slightly higher dissolved oxygen requirements than other fish and can get in trouble sooner if DO levels start to sag suddenly.

When my bloom died back due to weather changes recently a dozen of my SMB got very stressed, I also had lots of my larger GSH piping on the surface and one single yellow perch. Interesting that I never did see a single RES piping at the surface. I did end up with 8 SMB morts in the 14" to 18" range, 3 GSH in the 6 to 7" range, and that one 11" YP.
Posted By: SetterGuy Re: Aerate in the day or at night? - 07/13/16 07:19 PM
One thing I've noticed when catching SMB now, they still look great, and fight great, but seem more slick or slimy when holding them. I think it may have to do with the warmer water at the surface, but 2' down, it's still pretty cool.
Posted By: snrub Re: Aerate in the day or at night? - 07/13/16 08:48 PM
I know when we are swimming and get within about ten or fifteen feet of the diffuser we can really feel the temperature change from the cooler water coming up from the deep.

I would have to think that size of system make a difference also. For example on a given pond say system A would barely have the capacity to turn the whole pond over every 24 hours (or maybe even undersized and longer than that) compared to system B with twice the capacity that would turn the whole pond over in 12 hours or less. With both running 24/7 he smaller system might never completely homogenize the water temperature from top to bottom where the larger system could?????
Posted By: canyoncreek Re: Aerate in the day or at night? - 07/13/16 08:58 PM
again, depends on what the surface temperature is. If you are in texas and surface air is 100, you don't want 'homogenized' water as you super heat the water throughout. Having some area for cold water refuge or in general keeping ALL the water cooler is the goal. In northern ponds we tend to get cooling in the evenings enough that it makes sense to try to expose the water to that cooler temperature.

Also, many of us have 'shallow' ponds around 9' with less chance of thermocline creation and less risk of a zone of poorly oxygenated water.

Deeper ponds with significant stratification do want complete turnover of all pond water to help prevent the stratification.
Posted By: canyoncreek Re: Aerate in the day or at night? - 07/13/16 08:59 PM
Originally Posted By: Shorty
I still have some nice smallies present, I caught a 17"er a few nights ago and had a big one throw the hook last night. I am going to add a few HSB this fall just to make sure I am not short on predators.

Here is a picture of two low DO stressed smallies, this was the day after a very strong cold front with rain that came through, my water went from very green to brown during the previous day. Secchi dish readings went from 9" to 14" in a short amount of time. I am pretty sure the lighter colored one on the left was one of the ones that didn't make. I had a dozen SMB behaving like this the day after the front came through and I know that eight of those didn't make it.




Shorty, what is that brilliant green plant visible on the shoreline in your picture? Looks nice.
Posted By: snrub Re: Aerate in the day or at night? - 07/13/16 09:44 PM
My ponds are not over 10' depth anywhere but they definitely will get a thermocline and bad lower water without aeration when the wind dies down in the heat of summer.

I remember one time swimming when I was a very small kid in a farm pond that was very turbid from suspended clay. It had two thermocline. The first at about 2-3 inches and the top water was so hot if felt like it was scalding you till we splashed around enough to mix it up. Then another at about 3' where the water was hot. Then below that the water was very cold.

I still remember that top couple inches feeling like we were wading into boiling water.
Posted By: Shorty Re: Aerate in the day or at night? - 07/13/16 10:03 PM
Brome grass. grin
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