Pond Project Redux

[ootyboy]

Back in October I started a concrete pond project. The plan was to build a pond between 6 to 9 thousand gallons with adequate filtration for a light fish load. Looking back I knew I made some mistakes in the filter design and the overall look of the pond, and certinaly the choice for a water proofing membrane, that I was planning to resolve in this phase.

I built the pond using concrete blocks and a light plaster with the intention of coating it with Epoxy. I won't bother everyone with my problems with the Epoxy (see my other post about Epoxy coating). The pond worked relatively well, and held water for nearly 3 months. I did have to fill every couple of days, but the loss was rather small.

Here are the pond specs:

Gallons: 8000
Depth: 7 feet
Filters: Aqua Ultima 10,000, feeding into a Oases Biosys 18 and a small home made Filtration media with Bacteria House Media.

However, I woke up one morning on April 2nd, 2008 and to my amazement found that the pond had lost more than half its water. I panicked and filled the pond again, to find again the following day that I had lost more than half the water.

See Attached Picture.

After some research and hours spent looking for leak in the pond, I found a number of cracks in the Epoxy lining that was causing the leak. I figured my only choice was to redo the entire pond, and add additional filteration to enhance water quality.

The basic layout of the plan was to add possibly a vortex settlement tank and would feed into a couple of biological filters before going back to the pond. Anyway, to make a long story short I went back to the drawing board.

I will continue to post my progress on this board.

[ootyboy]

The next big question was how to line this pond. I really had 2 options, EPDM liner or Polyurea. Clearly, epoxy at this juncture was not in the running.

My first choice was a liner, mainly because of cost and ease of installation. I built a small pond using a EPDM liner and it has been holding up very well. However, my main concern with using a liner was the existing build of the pond, which was mainly concrete blocks and raised off the ground. That made hiding the liner at the top rather difficult, since the choices for rock work was limited to only 6" wide.

I then started to talk to a few Polyurea folks, and posting my interest on the Koi-bito forum. Since I am rather new to the hobby the consensus was clearly that Poly would be the best long term choice.

I decided after few interviews to go with Aquating Coatings Inc. (Jeff Dunkel).
I met with Jeff (since he lives only a few miles from my house) and we went through the steps required to get a nice coating on the walls. His main concern was that the Epoxy that was currently on the wall either has to be removed or covered before he can assure a good adhesion with the poly.

The other thing I liked about Jeff was that he was willing to share his experience with how to best setup the filtration. He made some constructive comments about my drain and filter setup and suggested alternatives that would best serve the pond long term. Here is list of what we decided:

1. Remove the 2" pump fed bottom drain and install a gravity fed 4" version
2. Install a Vortex settlement tank to remove solids from the bottom drain as the first step in the mechanical filtration.
3. Install at a minimum a 4" aerated bottom drain - with gravity feed.

I also drove over to his house, and saw his amazing 25,000 gallon pond with really impressive filtration.

As for my own project, after some research, I settled on a couple of William Lim Wave 36 filters, one for settlement and another filled with Japanese mat for mechanical/bio filtration.

I will post pictures of the project steps soon.

[koiczar]

You mention that Jeff suggested EITHER removing the epoxy coating or covering it for proper adhesion.
Was he specific about what to coat it with? If you really think you have a problem with the epoxy coating, REMOVE IT!!!!! If you don't, and it decides to separate from your block/plaster walls, so will the polyurea. Now, if you think you spent wasted money before, wait til this happens. DO IT RIGHT THIS TIME - DON'T LET ANYONE CUT ANY CORNERS or you'll really be sorry.

Secondly, why only two Wave36 filters. Sounds like you'll end up mixing mechanical and bio in the same chamber - NOT GOOD!! The settlement chamber will remove most all of the heavy solids but not the suspended smaller particulates that WILL end up clogging your Japanese mat and keep it from performing as a PROPER bio unit. IMHO, 3 chambers is MUCH BETTER than two!

Mike

[KoiCop]

Hello ootyboy . . .

What Mike said: 3 tanks for settlement, mechanical and bio-conversion (each of which can be flushed to waste).

Best wishes,

[ootyboy]

Thanks for your replies. I agree, that 2 chambers are not enough for doing full biological, however, let me elaborate on the extent of the configuration that I had planned, and I think that would go a long way in answering the question about biological.

While the first Vortex would handle solids the second vortex will be as everyone mentioned, part mechanical and bio. This would then feed into a Ultima 10,000 filter, which for a short period of time will be my bio filter ( hold off the dogs -- I know this is not the best plan in the world). The plan in the next month is to build a Bakki Shower in the waterfall tank, and therefore going directly from the second vortex chamber to the Bakki. The one decision that I have not yet made is whether to keep the Ultima 10,000 in line or just remove it, since I lose quite a bit of water pressure with the Ultima in line.

I've already purchased the media, but I am waiting for the containers to arrive in the next couple of weeks. The plumbing for the Bakki will be in place shortly.

As for the epoxy coating, Jeff's ideas was 2 fold. One, that my surface was not very smooth, therefore even removing the epoxy would make the overall look choppy. He suggested nailing in 1/4" cement boards to the concrete to use as the coating membrane.

For the bottom drain I decided to go with a Rhino II 4" aerated bottom drain that based on my research is one of the more popular choices for bottom drains. This will be connected to Alita 80L pump (which will also serve a few air stones in the second Wave 36 with Bio Media).

The next step was to dig the trench to the pond, since the filter area was more than 30 feet away. Since my quarantine tank was rather small for my fish population, I wanted to minimize the amount of time that the fish had to spend in the small tank, but doing all the prep work ahead of time.


I will continue with more a bit later!!

[Geishakoi]

Hey Mike!

Relax, let the guy share his pond with everybody. Nobody coated over another coating. The material that was put up was backerboard shot in with a Hilti gun, and we have done this on several ponds. Works out really good on vertical surfaces that have multiple issues. I am sure he will post pictures for you. He has limited space, so he'll control the flow through the vortex by increasing the flow with the skimmers. He did not want to add more pumps because of the electrical expense. He has a real nice pond, and he is going to watch his fish load until he can increase his filtration with his bakki shower.

So sit back, relax, have another smoke, or whatever you do????????

[Russell Peters]

Quote: Originally Posted by ootyboy After some research and hours spent looking for leak in the pond, I found a number of cracks in the Epoxy lining that was causing the leak.

After reading your post many times I think you hit on the real problem and don't even know it. Why did the epoxy lining crack? If you put an epoxy lining on a solid substrate that does not move or expand there would be no reason for it to crack. Linings don't crack unless it is the result of some other action.
Your epoxy lining cracked because your block wall cracked. Why did your block wall crack? Was it done properly? Were the footings designed to support the load without any movement? What was your rebar schedule inside the block wall? I would wager you that your epoxy lining cracked because your block was not properly constructed.
Just a thought. I am not pushing one product one way or another but a product is only as good as the surface you put it on.

[Nancy M.]

Quote: Originally Posted by Russell Peters After reading your post many times I think you hit on the real problem and don't even know it. Why did the epoxy lining crack? If you put an epoxy lining on a solid substrate that does not move or expand there would be no reason for it to crack. Linings don't crack unless it is the result of some other action. Your epoxy lining cracked because your block wall cracked. Why did your block wall crack? Was it done properly? Were the footings designed to support the load without any movement? What was your rebar schedule inside the block wall? I would wager you that your epoxy lining cracked because your block was not properly constructed. Just a thought. I am not pushing one product one way or another but a product is only as good as the surface you put it on.

I have to agree with Russ, on this one, I have looked at your pictures of the pond several times, when looking at the cinder blocks, it looks as if you just painted them, there does not seem to be any plaster or chicken scratch, did you do a 100% fill on each cell with concrete? is there at least #5 rebar in every cell? Also what did you use to seal around the suction pipe going through the side wall?

I am sure Jeff will do a great job of spraying polyrea but the structures integrity still needs to be sound.

[Russell Peters]

Quote: Originally Posted by Nancy M. I have to agree with Russ, on this one, I have looked at your pictures of the pond several times, when looking at the cinder blocks, it looks as if you just painted them, there does not seem to be any plaster or chicken scratch, did you do a 100% fill on each cell with concrete? is there at least #5 rebar in every cell? Also what did you use to seal around the suction pipe going through the side wall? I am sure Jeff will do a great job of spraying polyrea but the structures integrity still needs to be sound.

Hi Nancy,

The reason I posted this is because the product used was put down on another thread. I think it is important for everyone to know that the product is a good product but could only perform as well as the substrate that it was put on. Not all products are correct for every application.

Taking that into consideration, I agree with you, I think that Jeff will take the time to do the job well.

[ootyboy]

Russel, are you saying that you can actually create a concrete sub-surface that does not crack? I can tell you that I am not a concrete expert, but I've spoken to many concrete professionals, and the one certainty with concrete is that it WILL crack. It might not be today, or tomorrow or even five years from now, but it is guaranteed to crack, regardless of the amount of rebar that you use.

This is especially true in Northern California, where the ground moves quite a bit, and at least where I live, the soil is hard clay which hardens in the summer and expands in the winter with rains, causing cracks in walkways, walls etc.

Now we all agree, that Epoxy for all its merits, does not flex. If the structure moves as a result of settlement (which cannot be avoided), or ground movement, it will fail. No amount of concrete work will solve that problem.

However, the main point of this thread is not to talk about Epoxy or Pond Armor, but rather to share a narrative of my project with the group. As such I will continue....