Backyard Aquaponics
A place to discuss aquaponics

If I can put in two cents worth. The air in the aquarium filters is to cause flow in the under gravel filter but if you use the air stones and get fine bubbles also it helps aireation.

I love the comparison. I just finished reading this thread. I would like to see a page like the one where people told about the plants that like Constant Flood but for plants that like Flood and Drain better. Better yet would be a chart that shows which plants like CF and or F&D. I like the Flood and Drain best myself.

Great work. Keep it up.

There was a plant thread started don, good luck finding it though

I was a little wet behind the ears

Oh, I get it, you were so irritating that they dunked your head in the tank to use your ears as aerators.

Sounds like a good use for irritating youngsters

Don look here - they started a thread a few months back (probably amongst others)...

viewtopic.php?f=3&t=9032&st=0&sk=t&sd=a&hilit=preform+constant+flood

my theory is still that dissolved oxygen will be highest in the Auto Siphon, then Timer, and finally Constant Flood as the lowest. I think the surface area of the water draining over the gravel will greatly affect how much oxygen is absorbed.

I expect that in this situation where all three systems are using the same size pump and all have supplemental aeration, that yes the autosiphon system is getting more aeration because it has the constant pumping plus the flood and drain action in the grow bed.

I reckon the constantly flooded might have higher oxygenation because of the constant splashing into the tank...

But I'm not willing to get out the DO meter and calibrate it to try and find out for sure..

Bah humbug! With electricity prices here in Hawaii being some of the highest in the world it would be quite beneficial to find out.

i have a cheap and easy DO test, real accurate too

Step 1 - stick head in water, open eyes, and breathe in

if you cant breathe, and fish are dead, not enough DO
if you cant breathe, and fish are alive, DO is good.
If you can breathe, DO is to high, and fish are probably dead.

Trial System Data & Progress Photos 30-05-11

Trial System Data & Progress Photos 07-06-11

So do we think that after all systems leveled out at PH 6 or lower, after the recent rain it has come back up to Ph 6.4 or could this have been caused by something else. Is there any shell grit in any of the systems?

I think indirectly yes... More to the point, we aren't adding the bore water which has a very low pH... I think our bore water was around 5.8 or something? I'd have to check, but it's damn low..

Ah so the top ups have been made using the bore water that would make sense.