It has been a long time since I have been here, or really activily trying to maintain a tank. I recently decided to get back into (end of summer). Things were going well, then my light broke, I got a new T5HO fixture and things were looking even better than they had been. Until now. Over the past few weeks the certain plants have been going from bad.. to worse.. to non existent. The following plants are doing very well; riccia, ludwiga repens, blyxa japonica, (a crypt, anubius and java fern - but those really can almost not be killed for me for some reason). The star grass is marginal.. it's not really growing like it was, but is slowly growing and not dying. The ludwiga arcuata is pretty much stalled and seems to be stunted - the top are very small as before it was growing quite large and full. The biggest problem of all of them was the E. Stellata. I have 6-10 stems growing well and now, nothing. Everything melted slowly and I am down to 2 top of stem I am desparately trying to save.
ph is at 6.6-6.4, kh is around 3 or so. Drop checker reads a slightly greenish yellow (def. more yellow than green) - this has a homemade 4dkh (might be off?) fluid in it.
I dose EI at 1/4tsp KNO3, 1/8tsp KH2PO4, 1/8tsp K2SO4 (just started that this week) and 1/8tsp of Plantex - all 3x a week on opposite days.
50% water change weekly (generally speaking).
2x 39w T5HO lights on 10 hours a day.
As I said, most things are growing well, but the ones I REALLY want to be in there aren't. I some thread algae, but not even close to bad (this is also new in the last little while - sort of similar time line to the other problems).
Do the problems in these plants in particular and the algae point to something in particular deficient or excessive? I am at a loss and being in Canada I don't really want to lose any more plants as they are not terribly easy to obtain. I cannot really pinpoint when it started going bad.. I seem to recall adding some seachem equilibrium a couple of weeks in a row and that is when I _think_ it took a turn for the worse. That was a month ago though and I have not added it since. I wonder if it could be that or perhaps a the filter needs cleaning (1.5 months since I cleaned it last)?