Backyard Aquaponics
A place to discuss aquaponics

love the fishies =)

scotty, care to elaborate? The iron deficiency you are seeing in his kale, just due to the lightening of the leaves to lighter green? I'm still trying to figure out problems with my system and learn the signs to watch for but every time I take a picture to post to get info I forget to post it.

Apparently I miss ID'ed the plant it's not Kale but Broccoli, very similar in appearance and actually the same species but without heads on the broccoli it's sometimes tough to tell (Brassica oleracea - https://en.wikipedia.org/wiki/Brassica_oleracea).

If you look at the photos from June 15th the third photo from the top - look at the furthest tub planter and the very first plant toward the right, the one nearest the camera in that shot. What you notice is that the leaf sticking out toward you is darker than the other leaves, it's also lower down which indicates it's an older leaf in this case. The higher up leaves are lighter and you'll see the lighter upper leaves in some of the other plants and in the forth picture as well, indicating the iron deficiency.

You need to be conscious of the fact that some plants grow upward out of the center and others grow out away from a starting point. Knowing how the plant grows helps you know which are the newer leaves. From there you need to know which nutrients are mobile and which are not. Mobile nutrients can shift from the old growth to the new growth so deficiencies in these show up first in the old growth (potassium would be an example of this). Non-mobile nutrients aren't easily moved from the old growth to the new growth so deficiencies in these show up in the new growth first (iron is an example of this).

So that's how I figured it out and that's how you can figure out most problems with nutrients in plants although most are trickier than this.

thanks for the explanation Scotty. So I've read iron is not accessible at higher pH levels. Last time I tested my pH I was running someplace around 8 which appears to be too high for my chelated iron to be accessible (the amazon listing says it is Fe DTPA which they have a chart that shows Fe DTPA goes up to about 7.5, so I assume that means above 7.5 the chelated iron won't be readily accessible to the plants which might be part of my problems.

I've had a number of romaine lettuce plants that go from being green to getting little brown specs on them then a few days later they were completely dried out and dead. It has happened to me a few times. I'm debating if I need to do something to lower my pH, I prefer to just wait it out and let it come down naturally but I have not tested my water out of my hose that I'm using to top up the system and I think it might be directly plumbed to the well pump/storage tank, not running through the water softener for outside hoses, so then I'd assume it's pretty hard water which would probably be fairly high pH, so natural bacterial activity may not be capable of dropping the pH down fast enough.

Is there some iron additive that can be used over ph7.5 or is it a case of having to lower the ph?

EDDHA iron chelate should work for you Pete. DTPA iron chelate might work as well but is marginal at this pH. Spray application can be done to avoid the pH lockout issues in the system water so if you can't find what you need this is always an option.

Hi Guys it appears I have high ammonia , I found two dead fish today 8 hrs apart so tested the water.
I thought I could do an immediate 50% water change or move the fish to another system.
What do you think?

The problem may be your pH since the kit only reads down to pH 6.0, it could be a lot lower than that. It's unlikely that the ammonia is actually a problem at this pH but you do have to be careful adjusting the pH up or it could become one if your water temp is high enough. Check the chart in the IBC of Aquaponics. Muriatic acid (aka Hydrochloric acid) works well for adjusting the pH - do this a bit at a time and it's better if you don't adjust the system water directly (take portions out, adjust to whatever pH and then put back into the system to make change this way you won't overshoot).

High nitrates aren't the best either but usually don't kill the fish, still I'd try to get them down to a reasonable level, say around 40 or lower.

>> Check the chart in the IBC of Aquaponics. Muriatic acid (aka Hydrochloric acid) works well for adjusting the pH

In this case the pH needs to come up so you need to go with Potassium Bicaronate / Pottasium Carbonate or one of the Lime products. Or combinations of both. You will get the KHCO3 no problem up the road as it is common in wineries, beer etc and you are in the right location for that

This is a classic rainwater issue - pH can dive suddenly when nitrates go up.
Mostly a lack of buffering capacity.

The fish wont be liking the acidic pH - which maybe lower as Scotty notes.
(I suspect 5.5-6 is quite likely)

Didn't you have heaps of pH8 water when doing your other system Pete ?
You could just go with shandying that.

Pete, do as Darren suggests, that's what I was after. Thanks Darren, I must have been pretty out of it to suggest the muriatic acid .

Thanks Guys,
I was pretty desperate last night so I did a 50% (pond) water change, checked it again this morning with another couple of casuallities so I decided to move them to Sy2.
Lost 5 between 7 and 8" but now they're residing in the freezer waiting for the weekend BBQ.
System 2 has the most mature plants and now the most fish although some of the largest ones will be going next door to Sy1 as we will be consuming them faster now.
I'll look into your suggestions for future ref.

After battling cabbage moths and aphids through Spring and early Summer I lost 50% of the Broccoli and 90% of the cabbages. As the season changed and I ripped out the old and planted seedlings I considered what I could have done better to increase the yield.
Since I transferred the fish to the larger systems I've had no more losses, I let the plants chew up the nutes, added beans and tomatoes and I'm now running it on Seasol Power Feed until late March when I'll buy another batch of Trout.

Pete what were you doing to battle them? Manual removal? What worked for me in the garden this year was I had a second small bed that had cabbage and broccoli in it and when I noticed the big bed getting infected I sprayed with BT in the big bed and they all disappeared within a day and didn't come back until nearly the time I started harvesting so we only lost a little bit of broccoli at the very end after we had already harvested quite a bit. I left the small bed that wasn't growing very good as a sacrificial bed then only had to apply the BT once. Did the same for tomato horn worms I sprayed down my tomato plants with BT when I sprayed the cabbage/broccoli the first time and I never had horn worms in the garden this year but did notice there were a few tomato plants growing in my compost pile that I left alone which were covered in tomato horn worms but never saw them in the garden.

I was surprised this spring with how many cabbage moths decended on my AP setup compared to last year when I had much more Broccolli. It was as though the word got out that there's a free feed at Pete's. I should have netted the systems.
The aphids did the most damage though they were everywhere this year and none last year. I used Neem oil which eventually killed them but also turned the tops of the cabbages to a light green and rotting goo. Even the ones we deemed perfect to look at were damaged inside rendering 30% useless. Wont be wasting space on cabbages again they're cheap enough in the supermarket but consume so much space in the GB's.
What is BT Rob?

BT is a bacteria that is supposed to be harmless to humans but it kills worms. There are different strains for different critters but this is the one I bought which does a real good job on cabbage worms and tomato worms apparently.

https://www.amazon.com/gp/product/B009O ... UTF8&psc=1

Sounds like the dipel we get locally? Guessing the BT stands for Bacillus thuringiensis var. kurstaki which is what dipel has?