Backyard Aquaponics
A place to discuss aquaponics

hey seattle! I live in oly. my name is joe and i am a student at the evergreen state college. ive got myself set up with an independent learning contract to build a system and one of the aspects of my contract is to in tandem create a database of washington based aquaponics projects public and private. you mind if i send you some questions? also, did you come up with a solution to heating? did you try the heat sink?

Hey Seattle. I lived there fo years and understand the lack of sun. Now I am in N.W. Arizona and have an unheated greenhouse with AP. This year i am trying talapia for the first time and need heat. I have had them in glass aquariums with electriuc heat but they are getting to big and crowded. I hope to heat my 150 gal. tank for them. Last year I installed a tankless gas HW heater in my house to open up the pantry are and conserve propane. Now I have the used propane 30 gal HW heater for the fish tank.
My plan is to run water from the sump pump to the fish tank or thru a solinoid to the HW heater. The solinoid valve will open allowing pumped water to enter the tank and force hot water out to drop into the FT. The solinoid will be controlled by a thermostat in the FT. When FT temp is up gthe solinoid will close and allow sump water to flow past the HW heater and drop into the FT. The latter return will need be elevated enough to avoid bypassing the heater with vlave open. I will start with 100 deg. F in the HW tank and set the FT stat for 70 deg.
Later I will add solar to the FT but my need now is for night time and cold cloudy days. With solar I will still need this system as backup. The solar will have copper collector with antifreeze and alluminum heat exchangers in the FT. I will try it thermosyphon first but may add a solar hot water pump if required. In either case it will require an expansion tank in the return.
I am starting work on this today. Will report results later

So you'll be running a closed loop of water within the solar collector... and aiming for heat exchange to the tank via aluminium exchangers...

Soles the problem of copper contaact in the fish tank... but aluminium, in an acidic environment like an AP fish tank... probably isn't ideal either...

And aluminium isn't particularly efficient at heat trasnfer to water...

I didn't quite finish the job yesterday. Seems the hose from the prpane tank to the regulator is pluged, so need another trip for hardware today. The plumbing is in and the stat works. The little mag pump into the HW heater overflows and with the valve off the return bypasses to the fish tank.
Robt of Oz....alumimnum is a better choice than plastic or copper. If less efficient than copper it must be better than plastic, or the rubber auto heater hose I use for transfer. Sorry tro tell you but my FT is not acidic. My make up water is PH 8.1, FT runs about 7.5. My real concern is ethanol-glycol, antifreese, leak into FT. Therefore I will try to keep the collector lower than the FT to avoid pumping. I will try to keep the coil connectors outside of the FT.

I hope so....

The propane hot water system works fine. The stat comes on at 70 deg. F and warm water from the sump pump flow thru the heater and spills out into the FT to cut out a 75. The hot water heater control is not graduated in degrees so I have it set on warm and it runs to about 100 deg F at the outlet. I put one aqaerium of 75 blue talapia into the 150 gal FT yesterday about noon. At feeding time 4:30 none were floating belly up and FT temp was still 70 deg. So I went dancing. Today, if no floaters and temp is still at 70 deg. I will put the other 75, 1 1/2" fish in there.
Hopefully I will get to the solar booster next week. I dont know how much propane it will use yet, but the solar should reduce that quite a lot.