Backyard Aquaponics
A place to discuss aquaponics

If/when you do can you please redo your light measurements to see if you get a significant change. Cheers!

OK, so i'm reviving this thread...

I've been maintaining this system in various states of neglect and replanting, and always it seems to be the same. I've tried a few different lighting scenarios, some of which i have DEFINITELY grown something as simple as lettuce, so I know they're at least putting out enough light to adequately grow that sort of stuff.

The system has been running for a year and a half and as I had documented in a couple of other threads with some questions about things drying up and yellowing and generally just not doing well.

The nitrates have always been SUPER high, and when I tested today (after a LONG time since my last test...) they were again, blood red... PH seems to be really high as well, slightly over 8...

Originally the PH had fallen, as expected as it cycled. Got super low so I added crushed oyster shells. Unfortunately I was a bit of an idiot and just put a handful of shell grit under each of the outlets filling the grow bed. After a while the PH jumped to 8 or so and I assumed it'd settle out, since my understanding was that it should self regulate.

So tonight i dug up all of it and washed off all the shell grit. Hoping to bring the PH down over the next few weeks with some water changes, very light feeding, and adjusting the PH of the top off/water change water with muriatic acid.


Anyway, figured I'd revive this thread and document what HOPEFULLY will be a success story of how I turned this around and am now growing lots of veggies successfully like you guys!

A few pics as I continue to work on getting this thing on track.

I went away on vacation a couple weeks ago and threw a ton of black oil sunflower seeds that i normally use for sprouting into the bed, figuring they'd be good for nitrate uptake while I work on ironing out the system.

A series of massive water changes (85% or so) has finally brought the nitrate levels down from HUNDREDS of ppm into the 40 or so region, and a couple weeks of growth and very little feed has pushed them down even further to 10ppm or so.

Now that THAT is straightened out, I'm working on bringing the pH down to reasonable levels, as it's been >8 for the past year and change. Ideally I'd love it to be just sub-7, as i suspect that the >8 pH has something to do with poor lettuce growth as well as various other nutrient uptake issues contributing to all around poor plant production.

Also, I need it to come down to work on the iron deficiency that's become apparent (a year and a half with no iron supplementing, and it probably makes sense. I have some DTPA on its way to me, but the pH has to come down to at least 7.5 before that will be available to plants.

Iron deficient basil (otherwise it's growing reasonably well, from clippings of store bought "live basil" just jammed in to the media):



Purple potato that i put in there for sh*ts and giggles, since it was sprouting on my countertop anyway, growing very nicely:



Overall shot:

Might not be iron, could be potassium or magnesium defficiency. Need to get your PH down first.

What kind of feed do you use

I've been using aquamax pond plus 3000

and yeah, getting my pH down right now is my top priority. have been adding a few ml of HCl a day, mixed in to a bucket of tank water that I pour back in to the system when the siphon is draining over two or three cycles. So far it's come down a little, I think, but it's tough to tell with the colors on the high range, sometimes...

elegant setup. Crazy cool lights

Thanks, boss!

Yeah the lights are a homebuilt project cooked up by my old roommate and I. 3W LEDs in blue and red from SatisLED, and another set of 3W cool white LEDs above the "rails" you see in the picture.

They SHOULD be providing a decent amount of light to the plants, but i need to take some updated readings with some photo equipment and spectrometer to see what i'm actually getting to the plants.

So, good news. Small additions of HCl over the last week or so have finally brought the pH down to the 6.6'ish range.

I'll obviously be looking at this over time, but after a year and a half of running, ti was becoming apparent that the pH wasn't coming down on its own. I dug out all traces of oyster shell grit that I could find, and began adding small additions of HCl by taking a bucket of system water, adding 2.5 - 5ml at a time, and adding it slowly back in to the system.

Last night I finally saw what I was looking for, as I had been tracking it coming down from > 8 into the 7's after several days of this procedure a couple times a day.

pH below 7!!!!


I think my biggest issue with things not adjusting naturally over time is the fact that my plants weren't growing very well, which limited the amount of feed I could add to the water, limiting nitrification and natural acidification of the system. Ironically, my nitrates from the year or so of feeding reasonably lightly, yet with poor plant growth, had left my nitrates in the hundred and hundreds of ppm, which I now believe was hindering growth when combined with the low to mid 8's pH...

Alrighty. Next issue.

Leaf curling on my basil. I got the pH down as noted int he post above, which has allowed me to supplement chelated iron. This should hopefully help alleviate some of my chlorosis over the next few weeks.

Noticed today that the leaves on the basil are curling up. Thoughts?