Was asked for a micro dosing update on TPT so here goes. I'll summarize as best that I can. Anyone who doesnt care about a long rambling fert post which may or may not make any sense...might as well skip on down to the pics.
The last thing mentioned was the custom blend using .12 ppm dtpa + .08 gluc. That was maybe 6 weeks ago.
The next thing I did was eliminate the gluc and go to .15 dtpa. After a couple of weeks, several things didnt like this at all. I suspect the gluc might have been doing more than I gave it credit for.
The next thing I did was increase B a little bit (to 40 ppb) and increased Zn a lot (60 ppb)
The logic for doing this was because a few species were showing specific problems in the second or third set of leaves. Mostly small holes. Not K deficiency looking holes. Holes like snails make. It probably is the snails, but they wouldnt be causing damage if the leaf wasnt already in a weakened state.
So from internet research the most likely suspect seems to be Zn, or possibly B. I think Zn specifically because depending on where you look, it's listed as a "somewhat mobile" nutrient, or having a limited mobility.
My thinking is this might explain the issues with the second or third set of leaves. The plant can get more Zn from those leaves, but not from the ones on down like a truly mobile nutrient.
Speculation obviously.
Another thing I noticed about Zn is that Flourish Trace has an incredible amount of it. Dosed at .07 ppm Mn, it has like .169 ppm Zn. Which sounds crazy to me but there it is.
Well, since the custom blend uses all the same compounds as Flourish Trace and Comp, and I assume there must be a reason, it seemed logical that I might need to jack up the Zn.
So during the second week of the .15 dtpa blend, which originally had 27 ppb Zn, I made a separate solution of 30 ppb to add along with it - 57 ppb Zn per dose.
Only two things happened that I noticed. Ludwigia sp red got bigger. And AR mini variegated started putting out nice flat growth for the first time in months. Ive had 5 or 6 small ones just basically sitting there with twisted up leaves, not doing anything really. But in just a day or two they started putting out new growth all of a sudden.
That was two weeks ago. Some things had lost a little color since going down to .15 ppm Fe per dose. Not really deficient but I could tell they would like a bit more.
So the last two weeks have been .225 ppm dtpa, 3x per week, with B and Zn still at 40 and 60 ppb. Nearly everything seems to like it.
Here's some pics:
Pantanal in the 120. Most went to hell recently. The three tall ones are the only replanted tops that survived. The rest shriveled up and were cut down to stumps. The stumps are putting out nice new ones but this always happens so who knows