Backyard Aquaponics
A place to discuss aquaponics

Both BYAP, Murray and a few others have measured the standard timed flood & drain and siphon systems... and found DO levels to be more than adequate with just the water return alone...

Given that most people now stock at twice the once suggested levels, (with often half the filtration ).... and the common stocking of trout.... additional aeration with air pumps is probably almost a necessity... certainly desireable...

You can never have too much air... but you sure as heck can have too little...

I agree, finding cheap ways to inject air into your system are always good!

I guess this is where Cost Analysis comes in,

- Buy a pump big enough to cover the system and supply a return to splash/shower water
- Invest in a large aerator and plenty of stones
- run an additional pump to have showers (Bacci shower, or just a shower raining over the top of the tank)
- Run Venturi Aerators.
- Couple of ABF's in the tank (dual purpose)

Other Methods iv used

-Shower style endcaps on the end of my GB drains so rather than a stream into the tank/sump it has a larger splash zone & Particle breakup.

-Dropping the GB drains from a height to create more force into the water

these are ways that cost no more energy to run, and are probably more effective than a venturi or 2 air stones on a small pump.

Ahhh, Noooo....


Adding more aeration is not a way of stocking more fish... Higher fish stocking requires many different factors and extra air is only minor aspect.

Absolutely... and my post wasn't meant to infer you could add more fish if you had more aeration...

It was actually suggesting that many people needed more aeration, rather than just passive water return... because they'd already added too many fish.... for reasons for fish respiration, feed conversion and nitrification...

But additional aeration wont solve your problems if you're under filtered...

i never suggested it was to stock more fish.....

just like air in the system, plants love it, fish love it and these small measures can be quite productive.... just bought up the subject to try compile some more ideas on adding air to the system without adding another energy source.

Just don't want anyone browsing getting the wrong idea... I guess I have to deal with too many people day in day out with issues, and I've seen people get the wrong idea too many times.. :nervoustwitch:

Maybe we need a "Mad Scientists" section on here to discuss this kind of thing keep it out of the way of the GP

Hi All,

the methods of getting more air for 'free' may or may not work.

We never get anything for nothing. Yes no doubt these are all good ways to increase air/O2 into your system, but there is also defiantly a cost.

So cost analysis, is probably better cost/ benefit analysis. Ie how much cost to get how much benefit. This typically turns into a diminishing rate of return scenario. So how much money do we want to spend to get how much benefit?

Bang for our buck is what it is all about. Some things will cost a lot and give very little benefit. We need the things that cost very little and give a big benefit/return. Ideally spending less money to get more air, or whatever benefit.
Normally a bigger pump costs, both to buy and run, likewise for additional air pumps and stones.

If you put a shower style end cap does produce more particle break up but, is also a restriction so slows the particle velocity down. It may also, being an additional restriction, takes more energy for you pump to run. The same can be said for venturi aerators. If you have enough height/ head of water to create a flow capable of operating a shower head or venturi aerator then we have had to spend pump energy initially to pump it to that height. May be lowering GB’s and running an air pump might be more efficient? Maybe in this example we can get away with a smaller cheaper pump that also costs less to run?

Then the scenario where we spend more upfront, say a more expensive but more efficient pump, to get lower ongoing costs we can calculate our payback period. Generally 2 years is reasonable, and one year is good.

Energy is the big one we don’t often think about, at least initially until the bills come in. But it is definitely one to consider if we don’t to get caught in the future. Energy is the factor that is bringing large scale mono crop agriculture unstuck now which is starting to push food costs up, due to rising oil prices. This might get a lot worse soon with the Middle East destabilizing as regimes are toppling. We don’t want to get caught with our home AP systems that get more expensive to run as time goes on.

I am certainly not saying these are bad ideas, only that there is definitely a cost that should be considered/ calculated with them.

Just some thoughts.

Cheers.

I disagree.

Once when I was about 12, a friend and I were out on our bikes really early in the morning and we found an entire crate of flavoured milk and some magazines on a shop's doorstep.

Great weekend.

Hahaha

Hey sweet deal!

You da man. If you can go back and get some more of that count me in.

And thanks for pointing out the flaws in my thinking- there was me thinking I knew some things- what do I know?

Cheers.

Exactly OiB cost benefit analysis is the way to go. If you look at how many $/kg of O2 it costs then for the majority of systems on this forum then air pumps are going to be the most efficient/cheapest method of supplementary aeration. Those with pool conversions may want to consider a paddle wheel since they would have the space.

When I wanted to chose a pump I compared all the watts vs flow curves I could find. From that I found that the most efficient single phase pumps for total dynamic heads of Qaround 2-3 metres (most ap systems) where the laguna range. Now that constant flood is becoming popular the oase pumps that work best at a tdh of around .5 to 1.5m would be a more efficient choice if the system is designed/modified to suit. Or even (and if frank sees this world war three may ensue) an air lift if the tdh can be kept to this than a few cm.

If going constant flood then essentialy the ft and gbs could all be on the same level. As long as the pipes connecting them where large enough so that the dynamic head was only a cm or two then this would make ap systems much less energy hungry. Basically because lifting water is energy intensive (its heavy) where as getting air under water is relatively easy.

With that in mind, would having the return water splashing into a PVC pipe that goes to the bottom of the FT force more o2 rich water to the bottom of the FT. And if it did, would that water be more incline to move back to the surface.