In building a effective fish room I have bought products that exceeded expectations as well as failed miserably. So I'm going to give my two cents on how well they performed in my fish room.
I was looking for a way to heat my spawn tanks. Heaters take up a bit of room in the small containers I use to spawn in and I found it difficult to get consistent heat. Plus, the $20+ I spent on a heater only got me a few years worth of use, not a good return on my investment. The other drawback was all the power cords that needed plugged in somewhere. So, I went looking for a better way.
The water here in San Antonio is horrible, and even worse for fish. I struggled to get spawns and had many issues even with adults. I finally decided to get a reverse osmosis filter so I could control what was in as well as out of my water. After some searching and recommendations I bought this 150 gallon per day unit from Filter Direct.
Repashy Foods is a new gel based food that does not deteriorate in water. It allows your fish to eat all day long, much like they do in the wild instead of the gorge and fast they get being fed once or twice a day. I have gotten a small portion of this food and currently testing it out.