This is not to ansswer you but to share something useful i learned. It works with goldfish, so i think tropical should benefit too. You know how people get goldfish and they seem to go belly up easy A/K/A bloat? Well, brine shrimp is a good treat and keeps their tiny system in better working order. the problem is its costly and smelly. Well, i was taught that they LOVE peas. If you take a handful of frozen peas and soak them for a minute in water to thaw. then chop them up a bit and toss them into the water, the fish will eat them up and it keeps them from getting bound up which is why they die often. when i read this on-line, i was desperate as my daughter, then 15, went to bed crying because her goldfish was belly up and barely breatheing at all. I was ure it was too late, but i did it anyway. I went right to bed as it was 1 am. When we woke in the AM the fish was swimming around like nothing ever happened. If everyone who reads this, remembers it in the back of their minds, maybe it will save another little kids goldfish someday. Also, if you have fish now, just feed them chopped peas 1 or 2x a week and they will be happy and healthier for it. Plus frozen peas are easy to keep. Sorry this was so long, but I swear it works!!!