Backyard Aquaponics
A place to discuss aquaponics

Is there really a chance it could be the media? I always assumed lava would be pretty good.

Thing is, I set up a system in San Salvador in a plastic tub. Same media from my system and my biofilm, same pump and everything. That system has Green Beans and cucumbers and they are growing like crzy. The only difference I see is the amount of sunlight.

Well I keep hunting then.

VB I bought the 14 incher that way but the last owner said he was a year old. The female is the same size but has pop eyes.

Could you get a small sample of the gravel and fish water into a little bucket system with one of the fish, then put it into the sun? If this grows, then you know it's sunlight...

I have a feeling that lack of sun could be a major contributor to your problems, I have a barrelponics system on my back verandah and it has serious issues with lack of sunligtht, things do not grow well in the system. Another thought is to put some shade loving plants into the system and see how they go, if they grow ok, then you might reasonably assume sun is the main issue.

What about the flood times? are you letting the lava dry out a little before flooding again?

it either that or iron def.

Could you post a pic of the media up close?
Is it graded or all sizes mixed in one?

will do that in the morning but it is fairly close in size 10 mm to 15 mm

EB I have done both.

Test system in the sun works great.

Shade loving plants grow slow but look real nice. Will post pics in the am

The symptoms you describe are very similar to what I experienced when I put a little grow-bed on top of my aquarium which is nearly in full shade. Plants grew great for a short while - then got spindly - then died.

I think the general consensus is light but I will keep looking for chelated iron.

Is 7.8 considered high Ph?

I have a mason coming tomorrow afternoon to put in the foundation to move one of my growbeds into the sun. I will leave the other where it is for now. It will give me an opportunity to compare.

The rainy season starts in two weeks so that will present a new challenge. We expect 38 inches in 6 months. Then nothing for the next six.

It has only rained once since November 2006.

Chances are you will need iron anyway unless your lava rock has some in it. If you can't get the iron - you may be able to get some sort of rock dust mineral supplement.

I rechecked and saw you sieved it. so that would mean that you have up to that size maby 15mm. But what about the dust? did you re-sieve it to get out the particles that are too small. I mean the water WILL compact the media together an make it difficult for any DO to get in there or for roots to grow trough.

If it was up to me i would check for iron def. first then sunlight and then see if the media is 'good to go'

I will look around....
My brother lives an hour away and he has a hydroponic operation. Maybe he can sell me some Chelated iron. Just thought of that.

I've not seen chelated iron have such a drastic effect that it kills all plants, and I've run some of my system for years without adding iron.. 7.8 is reasonably high, but not of great concern I wouldn't think.

Thanks....another thing to check...good point CG