Hello, i have two tanks, one salt other freshwater. Both have hair algae problems. I went to the LFS
today and learned that the sally lightfoot crab is effective in controlling it. One of the guys at the store told me that these crabs are effective in both fresh and saltwater tanks. BTW, my freshwater is 55 gallons and the salt is a 50 gallon hexagon. How many crabs should I put in each tank for effective control. Thanks.