Backyard Aquaponics
A place to discuss aquaponics

After discussing backup power options for powering pumps, I was thinking about what actually happens when the power goes out.

In a continuous flow system, the pump stops and no water moves. A backup pump can be used to provide flow which is fine (probably less flow, but still ok). However for a flood and drain system, there are two pumps to keep going, so having two spares (and batteries etc) starts to get pricey.

After reading Gary's new setup, I though maybe we could use a seperate bio-filter. A seperate drum with bio-balls and a pump would provide filtration to keep ammonia and nitrites down (something like this pic from Gary's thread). There would be not water going to the growbeds, so nitrate levels would rise, but this wouldn't matter. Once the power comes back on, the plants would use that anyway.

The only issue I see is that the extra filter would need to be running all the time (to keep the bacteria alive), and need to keep running after the power goes out. The use of a small pump and a computer UPS would fix this though.

Can anyone see any problems doing this? I would think the more filter area available, the more fish we can keep in a system. It shouldn't matter if some of the bacteria are not in the grow bed, the nitrates will still get to the plants.

Nova

Nova, every thing you say seems pretty much right, but it would probably be simpler to have a spare pump on hand that you can change out if your primary pump dies?

A bubbler is a good emergency measure for Oxygen supply, and while i have no hard data i wouldn't think 1 day of minimal biofiltration would completely crash a system

I agree with Steve. Backup pump if pump fails. Bubbler if power fails with a small gererator to manually turn on to run grow-beds periodically in the case of a longer term power failures. If worried about pump failure though, would need to have a bubbler running all the time.

Actually, since i'm teaching everyone electrical 101, you could make a VERY simple flow switch to put into the power fail box, then yu bubbler would come on when power goes out, or flow stops.

Cont. flow would be easy, flood and drain a little harder, but not impossible

So oxygen is the most critical aspect then? A bubbler on a UPS should take care of that.

Would an extra boi-filter help increase the fish stocking levels for a system with less than ideal growbed size (1:0.8 fish:growbed)? It would give extra biofiltration and the plants would have extra nitrates to use. Some of the flow from the main pump could run the filter.

Nova

sort of, but then the system is out of ballance, you're only going to be able to grow so many plants, and their nitrate uptake will be less than the fish production, so its out of ballance becasue the nitrates will keep going up. see?

But for saving the fish in a power outage? YES O2 most important

Wouldn't more nitrates make the plants grow faster? Kind of like putting more fertiliser/urea on a crop? How much nitrate in the system is bad?

Nova

Not nessecarily Nova its like more boost makes your car go faster (until the engine blows )

I can't tell you how much is too mcuh, but pepole run thier systems any where between 40ppm and 100ppm

And there is also the fish side of things while nitrates are the least problematic for fish, huge concentrations will still affect them.

I think the guy at minnamurra was aiming at 40ppm nitrates

As far as the fertilizer goes, there is such a thing as over fertilization