Large strawberry hermit crab problem.?

Question

I have a large strawberry hermit crab in my tank. I also have a red algae problem, so we bought a sea urchin. It isn't one of the ones with the long spikes, I don't know what it's called. Well, we go downstairs and see the crab EATING the urchin. By the time we got the urchin off the crabs pincher, the shell was empty except fot the beak. What can we put in the tank to solve the algae problem, that the crab won't eat?

Answer 1

Little confused on your info - is this a strawberry hermit crab (terrestrial - http://en.wikipedia.org/wiki/Strawberry_hermit_crab ) with a saltwater section of his tank for bathing, or a strawberry crab (marine - http://en.wikipedia.org/wiki/Strawberry_crab ) in a saltwater tank?

I would guess the red algae is in the water? There's a chance this might not be algae, but cyanobacteria - also called "red slime". This is a bacteria, not a true algae. There are some kinds of red algae as well. In both cases, they produce mild toxins and acids, so not much will eat them. Even urchins have their beaks eroded by red algaes, so they would rather find something else to eat if it's available.

For both, you'll need to reduce the nutrients in your tank they feed on - this means more frequent water changes. A protein skimmer will help remove organic materials of this is a saltwater tank. So will a phosphate pad or polyfilter pad in your regular filter.

Cyano also doesn't like fast current, so adding a powerhead to move the water around may help. If you've got a saltwater setup, get some saltwater algae (caulerpa or chaetomorpha) to compete with the other algae for food. INCREASE the time your lights are on to promote the growth of the "good" algae.

If this is a true algae, try to identify the type by matching it with the species in this link: http://saltcorner.com/sections/guest/algaepage/algaepage.htm Use the numbers beside the algae your might be to find out which of the fish or invertebrates listed at the bottom might eat it. Reducing the light, or turning it off completely may help as well.

Unfortunately, there are no guarantees your crab won't eat any organisms you add with him. You could relocate a terrestrial crab to thoroughly clean the tank and substrate. You can't do this as easily with a saltwater tank, because you'll destroy the beneficial bacteria and you'll have to cycle your tank again - but this might not be a problem if there are no other organisms currently in your tank.

See links below for cyanobacteria and treatment/control and algae identification and things that eat the different kinds.

Answer 2

Naughty crab. Blue legged hermit crabs will help the problem. I use a tank vacuum to help get up the red algae that starts to develope in the sand in my 60gal tank

Answer 3

I have never had to salt my crab's water- they function fine without it... Thats the cool thing about hermits. try sea salt maybe if you think its totally necessary.. there could be other reason why he is "sick"