Hi Carp37.....Before joining this forum, I was concerned that my Ptergoplichthys juvenile wasn't getting enough greenstuff in his/her diet, therefore I bought a lettuce and put 4-5 small leaves of blanched lettuce in the tank. These were pretty much ignored for 2 days, then on the 3rd day the majority of the greenstuff of the lettuce had been eaten (not necessarily by the Pterygo), therefore I removed the remains of the lettuce, and added another couple of small leaves.
However, I had to remove these because the water clarity dropped markedly in the tank in a very short space of time. As yet I haven't got pH or nitrate/nitrite test kits- will get them this weekend, but does anyone have any suggestions to avoid water quality problems when adding vegetables? I noticed someone suggested raw potato, but I'm worried that this will also adversely affect water quality.