Here's what i learned....and I am a newbie too, but this was a big mistake...the pet store 'know it all' told me to stick these little algae tablet to the wall of the aquarium, as I have a non flake eating tang and needed algae, they didn't have the pads. I got the tablets, they are called Nibblers...well all the fish eat them....but not the tang. Go with the sheets, or pads. I'm still waiting for mine to come in. At the rate I'm going it would be better to open my own 'pet supply store' I'd be losing less $$$ on all my screw ups. This site should be a requirment to anyone doing fish.......seriously, It would have saved me a LOT of money. Also, those nibblers....I guess a nice occasional treat for the fish...they are messy and you have to watch it as the fish will overeat. I have the brown algae, was told it would develop into the green. Still waiting.