One tank grows like crazy!

I've a 150 that grows Amz. Swords & Vals like crazy but can't maintain Crypts.  A 120, with pretty much the same lighting cannot grow Swords or Vals but the Crypts thrive!  Any plant guru's out there to give a bread and butter explanation?  Bill

I am far from a plant expert, but I will take a guess. My first guess would have been the lighting, and it could still be different if the bulbs are older on one of the tanks.

I think it might be the substrate. I think the swords need to get more nutrients from their roots than crypts. I am not sure if vals are as picky. It also could be merely substrate depth, crypts have shallower roots, so they may not need as deep substrate.

I think in the 150 the vals/swords are probably out competing the crypts, rather than the conditions being bad for the crypts on their own.

Fair response Verb... FWIW.. the 150 with good sword and val growth has a substrate of PFS.. the tank that supports crypts is covered with fine gravel... I'll try new bulbs next I guess but really, I'm quite lax (lazy and cheap) and both sets of bulbs are probably aged quite a bit!... One note... the 150 has dual triple 3' t8's.. and the 120 has a dbl T5 4' fixture with a supporting dual 4' t8 fixture.... As it's quite late in the eve, I'll not disturb the fish to ascertain the K's nor watts... (yep... still up and ready to call it a "nite")... Bill

Oh.. and substrate is probably quite equal... 2"+