Backyard Aquaponics
A place to discuss aquaponics

Hi, I'm new to aquaponics, and have learned a great deal from reading your forums! (Thank you to all who contributed!) Would appreciate some advice on my system please.

I am setting up an IBC system, using 2 cut IBCs as grow beds, which rest on top of the IBC cages.
The IBC fish tank will use one 2,000 litre per hour pump to supply two grow beds. The grow beds then flood and drain (bell siphon) into the other supporting IBC tank as a "filtered water sump".

Since the water is pumped out from the IBC fish tank, the filtered water sump overflows via a pipe one way into the fish tank from the neighbouring grow bed sump, and the cycle continues.

This is where it gets tricky.. I also want to incorporate a 300 litre indoor aquarium that was given to me.
My plan is to pump half (e.g. 1,000 litres per hour or less) of the filtered water into the indoor aquarium, and let the other half (remaining 1,000 litres per hour) overflow into the IBC fish tank. I have a float valve which attaches to a small sump under the aquarium, which regulates the flow into the aquarium.
This works because the aquarium overflows down into the small sump below it inside the aquarium cabinet. It would be a disaster if the sump overflowed onto the carpet, so the float valve prevents that. (If the sump water level is too high, the float valve restricts water flowing to the aquarium, and therefore the sump does not fill any more).
Unfortunately there is not enough drop from the aquarium inside to the greenhouse outside, so I need to pump the indoor sump water out into the IBC fish tank.

I am concerned that if the water stopped flowing from outside for some reason (e.g. blockage, pump failure) that the sump pump would drain dry and burn out. I am looking for a solution such as a float switch to regulate the indoor sump pump to prevent this, and would prefer to use a submersible pump I have, which runs on 240 volt mains power.
The 12volt bilge pumps I have looked at say that they are not designed for contiuous running, or dirty water... To my surprise, I have not found a float switch which simply switches a 240volt power socket on and off.

Is there a simple way I can regulate the indoor sump pump so that it can't run dry?

I'm struggling to visualise this configuration -- in my mind something seems backwards or back-to-front? Can you post a schematic or photos of the system?

Starting the cycle from the IBC fish tank:
2,000 litres per hour to 2xgrow beds
Growbeds drain into other IBC container
Half of the filtered water is pumped to indoor aquarium/remaining half overflows into IBC fish tank
Incoming water to aquarium is restricted by float valve to prevent sump overflow
Aquarium overflows to sump below
Sump water is pumped out to IBC fish tank
(and repeat)

Should be ok as long as there is less water being pumped out from the sump than water coming in. I would have thought I could use a float switch to prevent the indoor sump pump from running dry if the water from outside stopped for any reason. So basically just wondering whether I can start/stop the 240 volt indoor pump with a float switch?

3 pumps?
in a word... yikes!

Yes Keith, the aquaponics system itself is currently cycling with a single 2,000lph pump.
The aquarium that was given to me has its own pump to cycle through filtration in the sump back to the fish tank above as a standalone display unit.
I figured that if I add one more pump, I can incorporate the aquaponics system as the filtration system instead.

Unfortunately due to the layout of where the aquarium is in relation to the sunny area of the backyard, I don't think I can gravity feed to the aquaponics system..
I could possibly dig the fish tank into the ground, but that would still only be a 1m drop over 23m distance, with some corners around walls. Would that even work? My main concern is water overflowing onto the lounge room carpet...

You're going to attempt to pump (highly) nutrient rich AP water through your indoor aquarium?

Just running an aquarium: it's hard enough to keep the nutrient levels in check so you don't get algal blooms etc without adding more nutrients from an AP system. In AP systems, everything will get coated in a green/brown slime layer of biofilm, a desired characteristic of a healthy and functioning system; the scourge of an aquarium as if you want to see your fish and the sunken ship and the treasure chest, you'll be cleaning the biofilm off the glass and the ornaments very often, greatly increasing the workload and diminishing the pleasure factor. If you expose the nutrient rich water to too much light, you'll end up growing algae and the water will turn to pea-soup consistency and all aesthetic qualities will be lost (unless you like looking at swamps?) Do you have lights over your aquarium? If so, this will only exacerbate the problem.

You'll find with the aquarium filter, you'll have some sort of mechanical filter to remove the solids, and some sort of biofilter to keep the ammonia and nitrites in check by converting these to nitrates; the nitrate levels are kept "reasonable" by some aquarium plants and/or chemical additives (not for edible fish) or by regular water replacements. I'd be keeping the K.I.S.S. and keeping the aquarium and the AP as separate systems; you can utilise the principles learned from one in the other though.

(I'm not sure if you know, goldfish (if that's what you've got in the aquarium?) are almost indestructable and can carry disease and parasites without being affected, but other species of fish often kept in AP systems aren't so tough, so before you cross connect, or put from one system into the other make sure you know the health of all the fish first to avoid spreading problems from one population to the other.)

As for the AP: I'd be tempted to run each IBC as a separate system. It's much more simple (K.I.S.S.), allows for different species/grades of fish to be kept, reduces problems with diseases/parasites and a few other benefits which don't spring to mind right now (there are very few negatives though, but the pros outweigh the cons imho). If you do have to run it as one system, I'd be tempted to join the tanks at the bottom to allow both tanks to maintain the same water level, with a single pump in one of the tanks. As you have it drawn, you're keeping the water level in the "sump" constant, and allowing the water level in the FT to fluctuate?!
The sump water is also aerated by the returning water, but this sits in the sump until finally overflowing into the FT, by which time, in a HSM scenario could be after you have pumped the FT (nearly) dry!

Very valuable advice, bunson! Lucky I have the benefit of your experience and wisdom...

On second thought I agree that I should keep it simple, and run the aquarium separately.

Thanks!