What will kill planaria, will also kill snails.
If you see 3 or 4 on the glass that means there are tons in the tank. Most tanks have them and most people are not aware that they have them. Once you see them on the glass, there are plenty in the tank. If you go with the no planaria or dog dewormer, remove as many snails as you can or you could end up with an ammonia spike from the decaying snail bodies. Also do not return the snails until several water changes later. I used it on a 2.5 gal tank. And even after totally emptying the tank and replacing the water, the added snails died within a day. It took 3 total gravel washes before the tank was safe for snails again. Since I have snails in all of my tanks, I will not use no planaria again. It did work like a charm on the planaria but within a month the first planaria showed up again. I believe they came via the gravel vac from other tanks. The planaria catcher did not work for me at all. Less food makes a difference but I doubt you will ever totally get rid of the critters. What I also found helpful is adding a flat rock, like slate. Planaria like to hide under flat rocks or decorations during the day. I remove these rocks once a day and wash them off. I am always amazed how many planaria I find this way, when in those tanks I don't even see them otherwise.
20g L46/hastatus/pygmy corys, 10g OEBTs, 10g blue bees/blue velvet shrimp, 10g CRS, 25g L174s/BNs/L340s, 10g yellow/red tiger shrimp, 15g clown plecos/CPDs/habrosus corys, 15g cory fry, 29g Weitzmani/panda corys/BNs, 46g L134s/salt and pepper corys/BNs/rubberlip pleco, 55g SAE/L201s/L199s/BNs/kissing gourami, 75g L316s/BNs/L134s/CAE/silver dollar, 30g L340s/L211s/CPDs,10g tangerine tiger/snowball shrimp, 20g L134/habrosus corys, 10g CPD fry
Last edited by garfieldnfish; 08-31-2012 at 12:58 AM.