Pond Boss Forums AERATION Should I aerate? Aerator cleaning reminder

A quick reminder to check your aerators. I have a small pond with a single compressor running through about 80 feet of weighted line to a vertex 2 head diffuser set at about 9' of depth. It runs 12 hours a day in spring and fall, about 18 hours in summer trying to pick the cooler hours of day and overnight. My pond had been very clear with running aerator or not in the past and since water is clear i didn't think the aerator would need frequent cleaning.

It has been on my to do list to get access to a rowboat and pull up the aerator for inspection and cleaning now that it has been in the pond year around for 2 seasons. I had tied a float to some twisted plastic string trimmer line but no longer could see the float so knew it may have disintegrated in the water.

I wanted to pull it up as I have struggled with muddy water all year (never had that the first 2 years) and although I suspect it is fish that is doing the muddying of the water, I wanted to make sure the aerator was well off the bottom.

Weather in W Mi has been hot and prior to Sunday night, no rain for about 2 weeks. Water was low so I figured a good time to check on it. With my son's help we were able to snag the edge of the aerator frame with a landscape rake and pull it up. We did this while it was running (not sure if it is OK to pull a running aerator above water) but we had no way to find it otherwise.

It took quite some effort to dislodge the black plastic housing from the bottom of the pond.

I was surprised that despite the appearance of normal 'boil' in the water that at least 1/3 or maybe a bit more of the membranes were coated with a tenacious clay/sand mix. I didn't have a brush with me so just kept wetting the clay and gently scrubbing with my fingers so as to not damage the rubber but to work it loose. After some time i was able to rinse it all off

I then saw no sign of any string on the housing. I had come prepared with some string and drill bits. Thanks to others on this forum I decided to elevate the housing a bit. I didn't have an old tire but had access to large plastic totes, the rugged kind that they ship car parts around in. I chose one that had 7" sides.

First I used decking screws to screw the vertex housing to the top of the upside down plastic tote. After cleaning and attempting to lower it back down i found I had issues with the housing and the tote being top heavy and it wanted to tip over as it went down to the bottom. The tote also trapped air bubbles. Example tote attached although mine was about half that height.


I hauled it back up and put some vent holes in the side of the tote and then also carefully made a hole in the flange of the vertex housing one on each corner. I then put some poly rope on each corner to make a four cornered sling of rope. I then put another rope from the center of that knot straight up with a pop bottle tied around the neck to float above that just under the water surface.

That helped as I could now lower by holding on to the pop bottle and it stayed better balanced on the way down (the air bubbling out as well) Once about a foot off the bottom i can let it go and i can feel it self-center upright as it hit the bottom. The pop bottle floats just under the surface and now it is much easier to grab with a rake and snag the popbottle and pull it up.

It took a couple of tries to 'guess' where the middle of the pond is to get it reasonably placed again but I'm happy I have a better system to retrieve it next time I clean it and clearly the boil at the surface is bigger with more visible bubbles when looked at from close up.

The other eye-opener from this project was as i was scraping around with the landscape rake on the bottom and pulling up the aerator box I released some clumps of VERY black leaves/debris. It clearly came from the bottom of the deep end and showed that there is a layer of detritus, old leaves stuck to the bottom. And this was right at the area of the aerator. No bad smell, just very black stuff.

Also, the handle of the landscape rake was hollow. As I pushed the rake straight down to the deep i could feel very warm surface water on my hands and then felt a current of markedly colder water come around my hands. I realized this was deep water coming up the rake handle creating a siphon. I was surprised that over only about 7-8' depth and with the aerator running that we still had this much temp difference. (I'm sure the perch were appreciating the fact that they could get to a little cooler water when they wanted to during the day). I figured with a shallow pond that the warmer temp would stay pretty constant through the water column.

So, on my to do list is:
1. Clean the aerator yearly (bring a soft brush next time although fingers work well too)
2. Watch for disintegration of the rope system and if needed change to light grade cable, providing the float can still float it up in the water column. Having this 4 sided rope system very much increases ease of snagging it later.

rain stirred things up with a lot of wind yesterday. I'm going to keep the aerator off to see if we can clear the water. Meanwhile, back to trying to fish/trap/net out the bottom stirring fish.

Thank you for that, Canyoncreek!

This was my goal last weekend as it's been 3 seasons, but with Blue Green Algae covering my pond I didn't want to get in the water to retrieve the diffusers

I know I can hook onto the weighted tubing from the boat but I'm leery about pulling on just the tubing to retrieve the diffuser.

Thanks again for the reminder and tips!

Keith

PS - 3 of my 4 diffuser sets are not producing bubbles like they used to so I KNOW they need cleaned. Any idea if I can safely pull on the weighted tubing to bring them up? The bases are filled with road gravel so they will be very heavy!

Keith,
I'm not sure the best way to 'snag' your aerator box. I had some crushed concrete pieces in my box to weigh it down. I wasn't sure I'd be able to snag it at all and was worried about snagging my aerator membrane with my metal-tined rake. The landscape rake has larger metal tines with flat tips rather than pointed tips like a bow rake. The landscape rake has closer spaced tines too. I just gently tried catching under the box and lifting it.

A weighted rope with a loop (lasso) on the end might allow you to hook under one of the diffusers and you could gently pull it up. The gravel doesn't weigh as much when under water so it will come up without too much force. It is best to let the water drain out before trying to hoist it in the boat as that WAS heavy.

I think I got lucky as some how the rake got under the small plastic lip on the side of the diffuser box. this is where the top half and the bottom half of the box comes together. There is nothing for it to grip but somehow the rake had continuous contact with one whole edge of the box and it continued to pull up as I slowly lifted it up.

Be sure you put a good stout rope, or cable and a float before dropping it back down. Even having a shoestring and a popbottle as a temporary fix helped me resnag it a couple of times with the rake much more easily before finally building the 4 part rope system.

My weighted rope is attached to the diffuser box with pvc cement and a hose clamp so if I had gripped the hose I was pulling gently enough that it would have probably been OK, but sharp objects vs the weighted tubing would not be so advisable. If you puncture weighted tubing right at the box you can always cut back a few inches and reattach. However if you pull on the weighted tubing from shore and the diffuser is embedded in the bottom like mine was you likely will just disconnect the tubing.. I think you would want to pull straight up and ideally not with the tubing only.

Thanks, Canyon!

From the shore I can loop a rope under the weighted tubing and follow it out to the diffuser (my bass boat is in the pond to aid in pulling), then pull up on the weighted tubing to raise the diffuser. And good tip on letting the water drain out of the base to lessen the weight!

And when I lower it back down I'll be using a plastic milk crate to raise it off the bottom.

Keith

PS - If I didn't have the blue green algae problem I'd just jump in and bring 'em up, if not just set them on a base and scrub them in place!

Keith,

You can turn off some or all but one diffuser which will add a lot more air to one unit which will clean it to some extent. Ted Lea showed me how to do that type of cleaning , but be careful to not over do it. IE make sure your pump will not damage the one diffuser that is left turned one during the cleaning. I found this worked well in my Topias when I had a diffuser in each last year. Now that the water is going down some this year, I will reset them and get them running.

highflyer is right. If you have a manifold you can 'flex' or 'burp' the membranes by routing flow to one and open/close to flex the membrane.

I only have 1 line, and one diffuser (with 2 diffuser membranes) so can't flex it. In my case, I doubt my 'mud' would have broke off. I had to scratch at it for a while with my nails to get the skin on the clay broken and then it washed off pretty easily.

Canyoncreek, I had the same issue of the diffuser base trying to tip over while letting it down into the water after building a base to attach the plastic gravel filled diffuser holder. And I also ended up using a four rope sling going into a single rope above the diffuser to get it dropped to the bottom without it turning upside down.

If I had it to do over knowing what I now know, whatever base I used or built I would put two eye bolts from two corners so that the eye was above the center of gravity of the whole unit. Then the unit would be bottom heavy and eliminate the problem.

I cleaned my diffusers earlier in the season, but plan to do it again. Would do it now by simply swimming down, breath holding, and scrubbing but also have blue-green algae in the pond and kind of scared of getting sick. I do the best job of cleaning when I don scuba gear and go down. Gives me time to work with the diffuser, evaluate any structure near, and place the unit right where I want it. It is kind of cool watching the bubble column from under water wearing a diving mask.

The diffuser definitely brings up cooler water. In the summer I can tell the water getting cooler on the surface as I approach the diffuser area swimming. In summer temperatures, the surface water will still be warmer than lower water as the sun heats the surface in the day time. The difference being with aeration there will not be such a definitive thermocline with such great temperature differences. I suppose if you had enough water movement the whole BOW could be homogenous, but that would likely take a lot more water movement than what is needed to turn the BOW once or twice a day.

It might surprise a person how much current is generated in a pond by wind and natural phenomenon. We may tend to think of the pond as a static pool of water, but many forces actually work to move the water around a lot. Aeration just makes sure the bottom water makes it to the top to take on oxygen.

Brian, Thank you for the reminder! Ted taught me the same thing and I've done that in the beginning of each season, but I know I've had more output than I'm getting now which is why I think they need a good cleaning.

But until I can get back in the water, I'll do that again for now and see if that helps in the short term.

Thanks again!

Keith

PS - There's also a chance, I suppose that my compressor is getting tired. I do change the filter about every 3 months, and currently running about 5 psi with all 4 going. It's been running 24/7/365 since 6-2012 (running only 1 shallow one in the winter with one open line to release some pressure)

Just as an update, (and I still can't clean the diffusers due to a terrible blue green algae problem), "burping" or self-cleaning the diffusers brought no results so I've ordered a rebuild kit for my pump.

I installed the system in June 2012 and I know I'm not getting near the output that I did then based upon the lack of bubbles coming from each station.

Hopefully the kit will be here by the weekend so I can try and get some water moving again!

This blue green algae thing is getting bad! So bad that I had to cover my mouth when I went to feed fish tonight because the smell was so strong. Tomorrow morning I'll be wearing my respirator. Scary bad!


Keith

PS - I'm working with Bill Cody on trying to get a positive ID on what this stuff is.

Mission accomplished with getting the pump rebuilt and the diffusers cleaned!

It's amazing how quiet it is once again, or maybe how loud it had gotten over the past 3 years but I just didn't notice it!

The cylinders were pretty scored and the cylinder cups basically shot, but somehow it was still pushing air!



The rebuild kit was easy enough to install and now running like it did when I installed it over 3 years ago .


Next up was finally getting in the pond to clean the diffusers.



I'm sure there's others more savvy with checking your compressor to see if it's performing the way it should (pressure test?), but on top of cleaning the diffusers, I would also recommend checking your pump!

Thanks again, Canyoncreek for the reminder!

FWIW I watch my pressure gage. I know what it ran at when first installed. When the pressure starts creeping up or down it is time to do maintenance. Most likely compressor (pressure down) or most likely diffusers (pressure up) but at least the pressure change lets me know there is a problem.

That's a great point, Bill D, thanks!

Although I wonder if in my case one was counteracting the other as my pressure gauge always stayed at 5 psi. Getting back-pressure from the dirty diffusers (pressure up), along with a worn compressor (pressure down)?

After rebuilding and reinstalling the pump, the pressure gauge read 9 psi. Then after cleaning the diffusers it's back down to 5 psi.

Thanks for the picture Keith. I wish i took a snapshot of mine, but your 'muck' on the diffuser looks more sticky, more tenacious. Mine was much hit and miss chunks, yours looks like glue all over the diffuser.

I haven't checked my air filter and will do that as I take the aerator off line this fall. I checked this spring and after 2 summers of use the air filter looked brand new yet. I have lots of pollen in the air and the water so not sure how the air filter stays clean.

if anyone wants to see another nice way to snag the diffusers from the bottom and be sure they settle back down straight when you are done esshup shared some of his experience. He has experience in this area and can offer some advice. Shoot him a PM.