I'm at the end of my rope with this tank. Every time I set it up, the exact same thing happens, over and over, and I'm trying to pinpoint what is going on.
Both my Rotala wallichi and Rotala nanjenshan look like this. Every stem I've planted before ends up doing the same thing. Even my crypt and marselia leaves are small and twisted up like this. I change things up, nothing.
I just set this tank back up about three weeks ago. The rotala have been in there for two weeks. They came to me in good shape with full leaves.
Tank: 29 gallon tank (30" x 12" x 18")
Lights: 3x 18w T5NO lights (2x 6700k, one rosette), directly over the water line, 6 hour light period
CO2: Pressurized co2 via Rex Grigg style DIY inline reactor
Filter: Eheim 2213, Koralia Nano 425 for extra flow
Ferts: EI for dry ferts, and 1.5 capfuls of Seachem Trace every week. There are some pFertz root tabs under the plants.
Substrate: Flourite Dark and Flourite Black. A small amount of crushed coral was accidentally mixed in (my daughter was "helping" me). I tried to remove as much as I could.
pH: 7.0 when co2 is off, 6.2 when co2 is on
The water is pure RO with Equilibrium (I did add a few gallons of tap when I first started the tank up, my tap water is like concrete). KH is from the initial set up and the crushed coral. KH went up when I started injecting co2.
Flow is good, all the plants are moving. The co2 is cranked up pretty high, the drop checker with 4dkh water turns bright green. There are no fish or shrimp in this tank, only snails. They seem largely unaffected by the co2. By the time the lights turn off, the tank is FULL of bubbles sticking to everything, including the glass.
The plants are suggesting a calcium/magnesium deficiency, judging by the deformed new leaves growing, and some plants have pale old leaves with dark veins. But I find that hard to believe, with the hardness of the water. I started adding Seachem Trace, thinking maybe there was something missing in the dry trace, but it's not helping anything.
I'm starting to wonder if it's the lights. I have them directly resting on top of the tank, but even then the DHG in the tank is struggling to grow. I have a hard time believing that the lights are too intense. The bulbs are old, I have not replaced them. Right now I'm wondering if I should buy new bulbs or just a new fixture (replacing it with a T5HO fixture). I can raise the lights above the tank, but that will probably be the end of the DHG. The stems are still fairly short, they are only about five inches closer to the light than the failing DHG.
Anyone see any red flags I'm missing?