Backyard Aquaponics
A place to discuss aquaponics

hehe you run a whole solar system. I'm barely the master of my own space.

I only had a head of 1m on mine and it was only producing 3kL/hr instead of 9kL.

My Jebao (22kl/h 175W) pump must have got some gravel (or something?) through the impeller in the past week - this has worn the impeller .

It is still pumping but at much reduced rates. Unfortunately i cant find a replacement impeller so have taken the plunge on a Laguna maxflo 16kl/h pump. I also ordered a spare impeller at the same time.

I am sure Stuart will support the decision


Bought the Jebao in 2011 so had good service from it.

I'll have the opportunity to compare the Jebao against the Laguna and report back!

Pump head question, probably one for Stuart.

I have a pump in the sump running approx 800mm of 25mm pipe from the water level in the sump up to the fish tank, If I were too put a second 12mm tube running from a tee in the sump 20 meters then up to the fish tank, what would the complications be?

So the head height would be effectively the same (800mm) just a longer run before the rise, that 20 meters of tube could even be lower the the sump water level if needed.

I'm going too go ahead and try it and see what happens, I sure there would be an extra work load on the pump, the water volume does not need too be pumped at a very fast rate, not much more than a trickle would be needed.

This whole exercise may be a total waste of time but I'm hopefully it will succeed.

I've been climbing scissor trusses all day in the sun and I've only just started my second coffee for the day so my brain is a bit fogged.

The 12mm run of 20m is to a different FT? You have said "the", as in singular, FT twice but I'm assuming there is a second FT.

The head loss will probably be less overall because the speed of water in the 25mm pipe will be less because some (not much) water will be going through the 12mm pipe.

If you add a valve on the 25mm pipe to restrict the flow in the 25mm pipe to force more water through the 12mm pipe then all bets are off and your flow will reduce dramatically.

Stuart thanks for the reply.

No there's no second FT just the one, what I currently have in the sump is 2 tees on the pump, the first tee controls the flow up into the FT by a ball valve running water back into the sump, the second tee also has a ball valve and was used to run a spray bar.

The old spray bar was removed 12 months ago leaving it sealed off with the ball valve and I want run 1 or 2 coils of 13mm tube in an Esky full of ice on the hotter days to help keep the temperature down in the FT. So instead of a spray bar running in the sump I will run that water through ice up to the FT.

Putting ice in blocks, milk bottles or bags directly in the FT lasts 5 - 10 minutes before it melts, putting the ice in an Esky the ice should last quite a while longer and with a very slow volume of water running through 10 or 20 meters of tube buried in ice I hope should help cool the FT.

The coil on the left is 13mm poly irrigation pipe that I filled with water and left in the sun to warm up and help bend it around the 150mm PVC but it still kinked and I'll replace it with the thicker walled flexible 13mm that I used on the right hand side coil.

I'll try just the right-hand coil (10 meters) in the Esky on it's own before I buy any more flexible pipe and see if it does in fact help cool the water and how long the ice lasts. The Esky could sit on the ground and that would put the 10 or 20 meters of pipe below the water level in the sump, if that would help or not I don't know or does it still become part of the head height?. Once I sort it all out I'll drill holes in the Esky and fit connections so the it all seals up and I can just add it to the system on hot days.

Stuart shoot me down if you think I'm wasting my time, you've save me from a few harebrained ideas before and I appreciate you advice.

whats the glass house happening

Short version....

I think you are wasting your time.

Longer version...

While the ice might melt very quickly in the FT it will still be doing as much as it can (ie not much ). Having it melt slowly in the esky won't allow it to cool the FT water more than it other wise would.

If you were running the coils through a fridge or freezer then maybe, maybe (huge maybe) it might be worth doing. Essentially to cool the water you need a refrigerator or heat pump to pull energy (heat) out of the water. To lower 1000L by 1C takes 4183kJ. To lower 1000L 1C in one hour would require a 1.16kW fridge (which is not the same thing as its energy draw because its a heat pump).

Using a chiller (fridge with heat exchanger running through it) is more efficient than freezing water and throwing it into the FT but it is still going to take a lot of energy to remove the heat from your system.

Sadly no but I'm still working on it.

I've built an irregular shaped FT. I really have no idea how much water it'll hold. I've imagined its volume next to a 1000 gallon (~4k liter) rainwater tank which is nearby. Really I do not know. I think I've read here that we want to turn the FT water over 1.5 times and hour? Since I'm guessing on the volume, and assume more is better than not enough, something along these lines... ?

Thanks for the reply Stuart.

I never thought it would be a miracle cure to the problem but an experiment before I went one step further, I have an old Engel running in the garage that I bought in 1980 and it will freeze water if needed and I was thinking of using it. There's also full size beer fridge in running in the garage and another smaller fridge in the pergola BBQ area so the old Engel is just the reserve in case I run out of cold beer

It has been running 24/7 since 1980 and has never missed a beat, I ran it trucks for over 20 years with a relay and it's own battery, it even flew in a RAAF C-130J Hercules up to Groote Eylandt in a truck for a month. It was turned off for both the flight up from Melbourne and the return flight and that's the only time long period of time it's been off since 1980. (6 hours each way)

Stuart the Engel has a bit of sentimental value and your "maybe, maybe (huge maybe)" comment has me having second thoughts about boring any holes in my old mate, if I can find a second-hand lid I'll go ahead or I might even try making a lid out of 50mm thick polystyrene and run the tubing out through holes in that before making the ultimate sacrifice.

My main concern was would the 10 or 20 meters of pipe become "head height"? and you given me on answer on that.

I'll have a play and see what happens, using the old Engel I could fill it with water and freeze it solid and be able to pump water through ice continually without it melting, then slow the flow down to just over a trickle, how much difference that trickle of water through 10 metres of ice makes to 900 litres of FT remains too be seen, I know it wont make a lot of difference if any and is it worth the effort?

Maybe dig or drill a hole and run the loop through the ground to cool the water would be better, I haven't tried it but at depths 4 to 10 ft, temp remains 50 to 60 degrees F year round. Ice might get you through a very short heat spell but that's it. I'd hate to see that fridge get a hole through the top.

Its all doable but the amounts of energy you have to expend to move the energy out of your system (cooling) or into your system (heating) is huge.

Refrigerators or heatpumps do this job relatively efficiently but it still takes a lot of power.

Not worth the effort with such a small fridge. If you are able to efficiently transfer heat from your FT into the 10kg of ice, you will get about 1 degree of cooling over what it would otherwise be by the time it is all melted. The most efficient way to do it would be to dump the ice into the water and not waste time and effort on tubes and pumps.
How many days running do you need to freeze 10kg of water with the Engel?

I put over 60kg of ice into my FT on some days in late 2013, that was enough for about 1C water cooling

Hi Joeblow,

What about setting up a cooling system using an old air con compressor?


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