Backyard Aquaponics
A place to discuss aquaponics

Happyfarmer, that is a good idea. My husband also came up with that, but I worry about having a sizable part of the system inaccessable in a closed loop in the cellar. It is Always possible to make a few access points, of course. But it complicates things.

For the moment I think I will keep it more simple and see how the temperature develops in the system.

OK, the replacement IBC (for the leaky white big tub) has arrived, plus the extra IBC. Unfortunately I won't really have time for the next one to two weeks to experiment. Patience...

Janna, head is measured from the top of the body of water from which the pump will operate, so in your case the head = (3m - depth of sump). You may not need as powerful a pump as you think you do.

PLJ, I would like to suck up the water from the bottom of the sump. Should I be able to hang the pump nearer the top (obviously not so high that it will run dry) and drop a hose down for the pump to suck the water from the bottom of the sump?

The head is measured from the water surface to as high as you are pumping to so you might as well let the pump rest at the bottom of the sump since it is the water level in the sump that determines where you measure head from if you are pumping from the sump.

Seriously I don't think you are likely to find a 10 watt pump that will move 1000 LPH even at 0 head. I have some nice little pumps that nominally do 1000 lph at 0 head but they are more like 20-25 watt pumps.

for an IBC fish tank system, seriously I would probably say go with a somewhat larger pump and move more water. I think you can find something in the 30-50 watt range that would be appropriate.

Now you say 3 meter head??? Are you planning on putting the grow beds up on the second floor?
To get 1000 liters per hour at 3 meters of head, you might just almost manage that with a 50-70 watt pump but only if you get a really efficient one and up size the plumbing and make sure it never ever gets clogged.

Hi TCL, Thanks for explaining again. PCL, sorry, I just didn't see it, but you said the same thing.

TCL, the greenhouse stands on a concrete slab over a 2 m deep cellar. For temperature buffering purposes it might be interesting to have the sump there. I figured it would be 3 m from the bottom of the sump to the top of the IBC fish tank.

I now have a 4000 l/h tank which uses 23-28 Watt. That is what the label says, anyhow. It is supposed to be a new generation super eco thingy. We'll see....

I'm guessing you actually mean a 4000 l/h pump which uses 23-28 Watt. Now a tank that could move it's own water might be kinda cool but sounds more like a terminator movie waiting to happen.

Your new pump, is there a chart that tells you how much water it moves at different heights? My experience is that x pump might be called 4000 lph and be able to move 1000 lph at 3 meters but Y pump might only be able to do 1000 lph at 2 meters. The trick is you really don't want to be using a pump on the extreme ends of it's pump curve since they are generally most efficient when used in the middle 3rd of their range. For example if a pump's MAX head was 3 meters, it would be most efficient to use the pump with a head of between 1-2 meters.

Now you say you are thinking of putting the sump down in the cellar. There is nothing that says you have to place the sump down on the floor. You could build a stand or table for it so the sump could be up high enough that you won't have to pump up so high to get the water back up to the fish tank in the greenhouse. However, have you considered putting the fish tank in the cellar too? Fish don't need the sun and greenhouse space is of most value if you can use it for the things that do need the sun.

Ah, wrong forum for the self moving tank... Pump it is, indeed. It didn't have a graph for the performance, but I am assuming a linear decline. These pumps use less electricity, the more head they need to pump... Can't wrap my head around that yet.

The celler under the greenhouse is rather hard to access. It has a very narrow manhole with just a few steps cemented in the cellar wall. No prime location for fish for that reason. But they are not going to be in the greenhouse either. They will be in the garage, which can no longer be accessed by cars because of the greenhouse now built before it and the veg dirt garden made on the lane. If you go to the first page of this thread, you'll see the layout on the photo.

Anyway, I am away from home for the moment, so it will be a while before I can get to build the system.

Back to working on the A P system. Cut the fish tank IBC bladder this morning.

Also tested (strip) the borehole water:
No NO2 or NO3 at all ( I'd have been surprised)
GH 16
KH 6
pH 6.8

Not exactly sure how important the GH and KH are.

I'll be flexing and cutting the growbed/sump IBC later today. Then we'll have to take apart a piece of the greenhouse to get the parts in...

Hi Janna,

Where do you live in holland? If it's not to far away maybe I want to come and have a look at your system.
I want to bild one as well so maybe we can share information.

PM'd Jai

Progress! A couple of days I had nothing much, but as I am having this week off, I got some work done on the system.

Below are pictures of the growbed (WIP)





The sump situated on it's proper spot, snugly positioned between the established inhabitants of my greenhouse (who, willy nilly, had to make place and be squeezed a bit more).

I've put some black left-over pond liner at the window side of the sumptank, but I need some more anti-algae cover.

The growbed needs to go on top of the sump, like in the IBC of AP video. I'd planned to cut a hole in the lid of the IBC, like in the video, but the pallet makes that impractical. It is a galvanised bottom plate and it has a reinforcement bar in the middle, smack underneath where the lid of the inverted IBC top lid would come.

Anyway, I tested watertightness of the lid. Just as well, for it leaked. So I put it on again with some fish safe sealant/adhesive on the rubber sealing ring. It made a satisfying sopping sound when I tightened the lid again, so hopefully this does the trick.

Finally, there is the fishtank in the garage. I'll put some bricks underneath to elevate it a bit and increase the height difference between the FT and the GB in the greenhouse. I still need to fix the two top bars with their bolts and then the thingies can be closed which will prevent sagging of the remaining top part of the IBC.



Some data:
FT: 1000 liter
ST: 600 liter
GB: 200 liter (?)

Got one bulkhead fitting today and instructions on how to install it. Hope to be able to get some more work done tomorrow.

Is the cellar a dirt floor or is it like a cistern?

It is like a cistern. It is a concrete hole in the ground, covered by a concrete slab. We're currently using it to store sand and we've used it to dump rubble, but that can be cleared if we decide to use it for AP.

The sump tank (on which the growbed rests) has lost some height, to increase gravity flow from the FT towards the GB.
I am now going to cycle using just the GB and ST in the greenhouse. Using ammonia.

You may want to look into cleaning out the cistern and sealing it to use as water storage and/or a temperature tank to help mitigate system water temperature fluctuations. What is your average ground temperature there?
You don't necessarily need to actually have the water from that mix with the system water either and a closed loop coil of pipe down there wouldn't require much energy to circulate.