Sorry didnít see your previous post, you didnít tag/quote me so it disappeared into the mist.
I was going initially under impression you moved mayaca out and did blackout on tank but your statement above makes it sound like you put mayaca in blackout?
But if you want my opinion I would have you go to daily low dosing.
Half gallon milk jug, 6 cups water, add .75ml Fluorish, add 1cup to tank per day to make up for evaporation. No dose on water change day.
KH2PO4, 200ml water, 1/8tsp for solution that you will dose 2ml per day except on water change day.
I really donít think the removing mayaca from tank was the cause, more like accumulative effect of dump and run dosing of ferts and unbound P and K in KH2PO4.
Itís about flatlined stabile dosing not hitting EI oriented specs. Feed your plants a low level every day and you wonít have a deficiency. In a low tech non CO2 tank the metabolic rate is so low itís nothing like high light EI dosing where if something runs out in middle of day your plant will choke and stall. All you have to do is make sure everything is there and never drops to zero for more than a day or 2. If you miss a day, no big deal double up next day, its low level dosing.
And I think itís time to move on from mayaca, itís a softwater plant. Itís never going to work in your harder water. Instead of P levels restricting uptake of iron I think itís potassium levels of SS blocking itís uptake of iron. Heck try some ambulia (Limnophila sessiliflora) or even some basic Rotala rotundifolia.
Besides ambulia and Val Nana I suggested before in your tank look at Willow Leaf Hygrophila. Itís marginal for size of plant your tank needs put itís doable. Planted under that spraybar itís leaves will sweep with water flow of that spraybar and look like a willow tree weeping out 6-7Ē or so into tank.
Take top right 4-5 stems of what you see in this pic and shorten them, imagine managing them as layered 4-7Ē stalks weeping out into tank. Itís easy to find, leaves are some of the most rugged leathery around and it has absolutely no problem with harder water. When it likes it habitat leaves at top under light will even get a nice pinkish/bronze cast on tips.
Whenís going good and has current flowing by/over it this is look youíll see when looking down into tank.
Also Iíd also like to see you add some crypt wendtii red or bronze or something similar in middle area of your tank. Thatís one thing your missing, a crown type plant that sets there long term and spreads roots all across substrate bed. Plant lightly and let those roots spread out across bottom glass for next year. To me there is no replacement for biological processes that happen in root zone of those type plants. Your mosses donít do that, your mayaca I doubt has even 1/4 of root structure they provide.