Backyard Aquaponics
A place to discuss aquaponics

^^ so many variables....so little time

Wow. In two days, my nitrates have dropped from 150 to 5. Ammonia and nitrite are still 0, and I have increased feedings from 8 to 10 tablespoons (50g) per day. What this is telling me is that keeping the pH in an appropriate range really helps things along. With such a sudden drop in nitrates, I am attributing the nitrate level to the anaerobic sand columns, not to the plants. I don't think the plants cared whether the pH was 6.0 or 7.0, but the bacteria does. When the pH got more favorable, they went to town!! So it is official, I am declaring the sand columns to be a success at removing excess nitrate as long as the pH is close to neutral! Hurray for the Really Smart Guy!

Regrettably, my pH has drifted back down to 6.6, but now I'm on top of it, and will figure out what I have to do to keep it on target.

sounds like the sand columns are a bit too good!

Yeah, I'm worried about that, Steve. I'm going to hold the pH steady and monitor for a while. If need be, I can remove one or both of the sand columns. It does occur to me that if the sand columns get rid of some of the nitrate, the balance of NPK may be better overall to get fruiting crops going. The important thing is that I've learned a control mechanism that isn't really too hard to implement.

Nice work Janet.... as always

PH?

I keep having a mental image of the sand columns going up and down like control rods in a nuclear reactor!

Steve, Well, Calcium hydroxide for the pH, and the sand columns for nitrate.

DD, you worry me.

Hmmm! I was thinking more along the lines of an accelerator pedal. Only problem is you can't stomp on it to speed things up, and you could have problems slowing it down. But overall, they sure help to get things going!

Kevin

Actually, I think if I slowed water flow down to the sand column, it would introduce oxygen to the top portion of the sand column, in effect, reducing the anaerobic area. So I do have a way of increasing/reducing the nitrate off-gassing with only a twist of my water distribution pipe in the bed. Spooky!!!

That was a quick fine tune!
Good stuff!

Janet,
Have you been keeping a notebook of all of the observations and information you have gained? Even if all it is, is a bibliography of source material it will be helpful for all persons interested in AP.

Good job, and keep it up!

Now! Let's get some size on those fishies! I want them up to 1 kg for harvest ASAP! We need to feed those girls!

Kevin

Wow! I have missed a lot those fish are huge. You have done such a fantastic job janet and it must be a please to see it all growing.

Doesn't look like you have a light problem as you first thought you might.

How have you gone with the breeding? any luck (sorry for not reading so far back but I have 8215 new posts, so a lot to catch up on).

Also do you have any updated pics of your outside pond?

Also good to see Pandora's well and hasn't moved from her watch.

Hi Kevin,
You are looking at my 'notebook'. It's this entire forum. Actually, if we can get the AP-wiki going, I think that will be my 'notebook'.

Hi Asitis,
The lighting gives me a problem with some food crops. Interestingly, lettuce gets so spindly that it falls over and just rots. Other stuff does OK, and I just re-planted basil and bok choy. Those do well for me. I've attached a pic to answer your question about how breeding has gone. (And this is the group I culled down from twice that many.) And I will post a couple pics of the pond in that thread--as soon as I find it.