rule of thumb for invert compatibility?

[freeNINETY9]

im going to set up two tanks on either side of my telvision that will probably be around 20 gallons each. ive had good luck with lots of hermit crabs and some camel shrimp but im looking to add to those. is there a rule of thumb about what can go with what?

i know big fish eat small fish so is it the same for inverts? and can you add more inverts to a tank with no fish...like, i know a fish tank needs to be less crowded as more fish are added but can you 'jam more inverts' in so to speak without any fish?

i guess what im looking for is a full, active tank if that can be done safely.

thanks for the replies.

 

[Atarax]

a general rule of thumb i adhere to about hermit crabs is if the claws are the same size they are USUALLY pretty mild mannered. also just make sure there are PLENTY of shells for them to move into otherwise they will fight and kill each other or snails in the tank. i know, i know, its common knowledge but thats all i can come up with.

 

[freeNINETY9]

yeah i have a lot of empty shells from mystery snails i kept in freshwater tanks for a long time. i know hermits generally get along but does anyone know about starfish? i kinda wanted to get one but i know some eat crabs, some eat eachother. brittle stars dont really fit what im looking for. maybe chocolate chip starfish or something?

 

[Atarax]

chocoloate chip and general stars eat coral. try a serpent star, they are real active. and look creepy when they strike a trot acros the tank. mine has learned to look for my hand in the tank and will grab my hand as if to say "feed me, you puke bag" pistol shrimp are really cool too. but not as much without a goby.