Hi everybody! I have a planted 55g that I'm having trouble with. My 25g plants are WEEDS, but the 55g has been a headache. I think its a lighting problem, but I'm looking for some opinions. Please and thank you!
Its a 55g blackwater setup. I have play sand as a substrate, and leaf litter. I have pretty hefty amount of driftwood. Its kept at about 77 degrees F, and I run an Emperor 400 with a prefilter sponge. The pH is 7.4. It has Limnobium laevigatum (frogbit), Pistia stratiotes (water lettuce), and about 18 Vallisneria americana gigantea (jungle val) presently. It has a single bulb fixture. Its on for 12 hours/day. It is lightly stocked and has MTS.
On 9.8 I started adding plants. The water lettuce and a few vals went in at this time. (I have slowly added more vals along the way. Most of the vals have looked pretty rough to begin with.) The bulb was a 40w T10, unknown K, and it was old. I knew I'd have to replace it soon, but since it was a T10, odd size, I was researching how. On 9.26, the water lettuce was sending daughters and looking good. The vals looked them same. On 9.29, I started dosing 4.6mL of Flourish Comprehensive weekly. On 10.12 I had a quite sudden die back on the water lettuce. The largest heads started losing leaves, and the roots totally fell off. Only the small heads were left. It was at this time that I had a nitrate reading of about 15ppm. Other than this, my trates have never been over 5ppm in this tank. On 10.13 I removed the first of three dead vals. I also started adding some frogbit from another tank to help with the trates. I've never had more than a 10"x10" patch of floaters, combined, so I don't think they are blocking too much light. On 10.12 I installed a T8 6500K bulb and added the last of the vals, but this batch was VERY healthy. Today, almost a month later, I expected to see that everything has bounced back. It hasn't. In fact, those healthy vals I added a month ago, even with the new light, are starting to look just as pitiful as the rest of the vals.
So, I've ruled out certain things as culprits: substrate, snails, pH, hardness, ferts. Things I have not ruled out: light, blackwater. I mean, my water isn't dark, its just a nice amber glow. (Well, it was until I installed the new bulb that has a much greater spike in the blue spectrum. Remember those old Ziplock commercials? Yellow and blue makes green? Yeah, well now my tank looks LIME GREEN. Its very unpleasant looking. But that's a whole 'nother rant. )
I'm thinking the solution is a 48" fixture with two bulbs. Well, that's my guess. I can't really afford that right now, and even when I can afford it, I don't want to waste my money if that's not the problem. So does anyone have any ideas? I'd be very, VERY grateful!