I have a 60 gallon fish tank that I've maintained for about 9 months. I started with 2 emerald crabs and they died and idk why. I later got 2 more and one died the first week I got it and the other died just recently after 4 months. I don't understand why they keep dying. I have a bubble algae problem as well. My tailspot blenny helps but it's still a major issue. I didn't have bubble algae until the first 2 emerald crabs died and I wasn't able to get more until 2 months later. The water perimeters are nearly perfect and I also have clown fish and mexican turbo snails that I've had from the beginning with no issues. I'm open to getting more organisms but I'm not sure what to get. I was thinking a Starry Blenny?