I don't know why I never read this thread before...
A note about Otos, yes they are hard to acclimate but I wouldn't say 50% of them die. I find my losses closer to 10-20%. The trick is to buy healthy ones. Stores' tanks are usually spotless and the Otos slowly starve. I can't even get mine to eat veggies, they NEED algae. I either buy them the day after they come into the store or from dealers who keep one or two in each tank for algae control instead of cramming them all in a super clean tank with nothing to eat. I float the bag for 30 minutes or so, open it, pour out half the water into a bucket and clip the open bag to the inside wall of the tank. Every 10-30 minutes (depends on what I'm doing) I pour a cup of tank water into the bag. When the bag is full I dump most of the water out into a bucket leaving enough to dump the fish into the tank. The whole thing takes an hour or two of waiting but if you're doing something else you won't notice. Doing it this way I haven't lost an Oto in the last 10 or so I've bought.