I have a question I have not heard addressed. Since I am a cabinetmaker by trade I plan to build an Aquaponics system with the tanks and grow beds out of plywood. I have searched the internet and been on many fishkeeping forums where people have built aquariums and fish ponds out of plywood and lined them with epdm pond liners, fiberglass, different brands of liquid rubber, and epoxy paints. I have also heard horror stories of the epdm pond liners and the liquid rubbers failing. I have very little experience with fiberglass but I know it is messy, time consuming and the fumes are very strong.
My question is about pickup bed liners. I have only seen a couple posts from people on fish keeping forums who were asking about using them to waterproof wooden fish tanks. I read one forum where a guy built a small experimental tank and lined it with bed liner. His last post was that it had been 30 days since he introduced fish and they were doing well. I know bed liners have been used for lining potable water tanks, and livestock tanks. Most of them are water based liquid polymers that are solvent free and contain no harmful VOCs or CFCs
I found the following applications online:
1. The long island aquarium built a 20,000 gallon aquarium in 2000 that has concrete walls that were “sealed with a polyuria lining much like the spray on bed liners for pickup trucks”
I just e mailed them to try to find out the name of the product they used
2. This guy built a 2000 gallon plywood fish tank in 2005 and lined it with speed liner brand pickup bed liner. He said it did well.
3. This German company apparently makes aquariums and uses rhino pickup bed liners to waterproof them but since I don’t speak German I can only look at the pictures. http://www.raubwelse.de/angebote/rhino.htm
I also got the technical chemical analysis from some manufacturers but not being a chemist I couldn’t read it although it seemed pretty safe by what I could understand. The manufacturers all say that it is fish save and can even be used to line potable water tanks and pipes. I guess my question is why are people using epdm which looks bulky, can allow water to get trapped behind it and can fail or liquid rubber which turns brown and can fail and fiberglass which is messy when pickup bed liner seems a much better option to me? Is it just because the other stuff has been marketed to fish keepers and Aquaponics growers while pickup bed liners have been marketed to pickup truck owners? I even watched myth busters try to blow up the pickup bed liner. The stuff is nearly indestructible. I just want to be sure before I spend the effort and money to build.
I actually planned on using fiberglass. I have never worked with fiberglass so I watched a bunch of u tube videos and talked to the guy at the auto parts store where I bought the fiberglass resin. Yesterday morning I mixed it up and lined the boxes. Today it still is very tacky in places and it is bubbling up all over. (Yes I remembered to put in the hardener lol) I used a good painters brush to apply it and I washed it out in acetone between each batch so I am pretty sure that is what caused the problem. So tomorrow if it is dry I will sand it all out and start again. I really didn’t like working with the fiberglass and I know the roll on bed liners are much easier to work with. I think I may just go ahead and buy some and try it out unless somebody has a very good reason not to. If it is safe for the fish, which everything I have been able to find out indicates it is, then I would feel very confident that I will have a beautiful trouble free system that will produce an abundance of healthy organic food probably long after I am gone.
Chip Pilkington said:
Good deal - please post pics, as you may have discovered a new option in tank construction.
Fiberglass is not for everyone and like most building and construction methods, it takes practice and developed skills. I had the opportunity to work with it as a teenager - dad had an old wooden boat he was restoring and guess who got to help! Anyway, Good luck - let us know how it goes.
Here are some pictures of what I have so far. This is before the fiberglass debacle. The glass in the fish tank makes it impossable to use epdm liner. also the silicone will not stick to the liquid rubber products like zavlar or sweet water so I am left with epoxies, fiberglass or bed liners as my options to line the tank and grow beds.
I sawmill/kiln dry/moulder/furniture etc. so I too have the cravings to use the wood work skills and integrate wood into aq.
Stave construction with t/g boards for the bottom makes a fish tank/hot tub.
But for economy I saw a scratch-n-dent 5 sided fiberglass bathtub (thats a tub with a fiberglass ceiling built in as one unit).
Or purchase a proper liner and put it in a well supported wooden tank (wood stringers across the top stop side bow and make a shelf).
Right now is the time to look for small swimming pools on sale,, 10'ish range can be had way cheaper than pond liner+labor materials to frame it.
If I were to go with pond liner or other sheet good, I would put it in a box as is, and not do any cutting or joinery. Yes that makes a fold over in each corner but so what.