McgJosh
i'm using 2 x 15 watts CF.
brnmix
yes it is bubbles caused by falling water from my filter. i'm not sure i understand what you mean by harmful? this is a non CO2 tank, but i have air pump with airstone at the other corner of my tank. without CO2 that's why i used easy plants only there. about photos, i'm sorry because the camera isn't available right now but i can tell you my simple system... top hanging filter, 30 watts CF lighting, air pump... that't is...
the tank is running for a week right now, slow growth on plants. tried some stem plants (bacopa caroliana, hygrophila polysperma) but the goldfish uproots them immediately or during the night so i gave up
tried to put some pellia tied on wood and the goldfish made a mess from it, releasing all the pellia but didn't eat them
life it's hard....