Crabs! When to Add and What to Add?

AKL1950 · Aug 4, 2022

My system has been up and running since early April, so about four months. I’ll be adding my last four fish next week. I’ve also introduces snails (20) about a week ago. I had my initial diatom bloom two weeks back, but it’s almost completely gone Now. Snails are doing a great job of cleaning up the rocks.

I have not introduced any crabs yet. I figure I’ll bump up my feeding next week with the new fish and thinking I need crabs now to help keep the place clean. Is this about the correct time to bring some in? Also, which ones would be best and how many?

DT is 167 gallons. Total fish will be 14. Four tangs, two angels, two clowns and 6 chromis. I want to start adding corals in late September. mostly SPS.

Current parameters are:
Temp 78
salinity 34.6
PH. 8.0
Alk. 9.8
NO3. 7.8
PO4. 0.05
I have not started testing Cal and Mag yet. Waiting till the corals start coming in.

I’ve still got the lights fairly low and mostly blue. Greens, reds and whites are below 7%. First pic is lights on and second is with a flash. The red rock is not coralline algae. It’s CaribSea rock. Only coralline in the tank is what came in with the snails.

So Crabs. What kind and how many?

Jetson

Crustaceon · Aug 4, 2022

Honest opinion: Snails are better. Get some zebra trochus.

AKL1950 · Aug 4, 2022

Got ‘em. Actually got the cerith snails and (mostly) red band trochus snails. Wanted to add some crabs with them. Just not sure if there’s enough left overs and junk in the tank to support them yet.

Tuan’s Reef · Aug 4, 2022

Well.... I normally hate crabs. They are just too opportunistic. I did not QT my frags and now i'm paying the price. I have bubble algae growing on my Zoa frags. I know emerald crabs will eat it but i'm skiddish about it. The last time i had emerald crab it picked on my hammers

AKL1950 · Aug 4, 2022

That’s not good. I was thinking more along the line of hermit crabs. Blue leg, red leg and scarlet.

Tuan’s Reef · Aug 4, 2022

thats the problem....the hermits. They always killing each other and your snails for shells. I've seen countless war fare my hermits mount. Its funny and not at the same time lol Its funny to watch ... but than your snails are dead

AKL1950 · Aug 4, 2022

Interesting. I’ve read a few other threads on hermits, and most people seem to agree that they are problematic. May have to kick that can down the road a bit and decide later.

Duncan62 · Aug 4, 2022

AKL1950 said:
My system has been up and running since early April, so about four months. I’ll be adding my last four fish next week. I’ve also introduces snails (20) about a week ago. I had my initial diatom bloom two weeks back, but it’s almost completely gone Now. Snails are doing a great job of cleaning up the rocks.

I have not introduced any crabs yet. I figure I’ll bump up my feeding next week with the new fish and thinking I need crabs now to help keep the place clean. Is this about the correct time to bring some in? Also, which ones would be best and how many?

DT is 167 gallons. Total fish will be 14. Four tangs, two angels, two clowns and 6 chromis. I want to start adding corals in late September. mostly SPS.

Current parameters are:
Temp 78
salinity 34.6
PH. 8.0
Alk. 9.8
NO3. 7.8
PO4. 0.05
I have not started testing Cal and Mag yet. Waiting till the corals start coming in.

I’ve still got the lights fairly low and mostly blue. Greens, reds and whites are below 7%. First pic is lights on and second is with a flash. The red rock is not coralline algae. It’s CaribSea rock. Only coralline in the tank is what came in with the snails.

So Crabs. What kind and how many?

Jetson

Female emerald crabs. Some hermits. Trochus is my favorite snail next to stomatella.