Blenny with crushed coral

[mcowan]

Hello,

I have an 8 month old 55g FOWLR tank with the following:

1 cleaner shrimp
1 coral beauty angelfish
1 chalk bass
2 clownfish
1 pincushion urchin
a bunch of snails and hermit crabs (8-10 of each?)

I would like to get some new fish. The problem is I have crushed coral. I had a canarytop wrasse but it died 2 weeks ago (I think maybe because I didn't realize it needed sand to borrow the CC just slowly deteriorated his health). I also had a cyanobacteria problem 6 weeks ago and the LFS sold me the urchin as well as a scooter blenny saying it would help. I later found out that the scooter blenny is a type of dragonet and requires pods - tried keeping him alive with pods and mysis shrimp but he eventually starved and died last week. Rookie mistake to trust the LFS. 8 months of a fairly successful tank then 2 fish die in one week =(

Looking for some hardier fish to add. I have two questions:

First, I was considering a midas blenny but I wasn't sure if he would be OK in crushed coral. Any experiences with this?

Second, should I just switch my CC out for sand? My nitrates never seem to go below 30 ppm (nitrites and ammonia are always 0). I've heard there can be nitrate problems with CC. I've read about different ways of switching to sand but I'm really nervous to do this considering that it might create a mini-cycle that could kill my surviving fish. My coral beauty has hole in the head (started 6 weeks ago when I got the urchin which got rid of literally all the algae in the tank - trying to supplement his diet now with algae wafers but he doesn't like them!)

I'm also considering a flasher wrasse - will he do OK with crushed coral?

 

[mcgyvr]

In general crushed coral is not suitable for sand sifting creatures and does not typically allow lower oxygen environments to form that some types of bacteria need to process nitrates..
Its usually "best" to remove the sand (in sections every couple days..) and replace it with dry sand of smaller size..

 

[thegrun]

I agree, I would siphon out 1/4 to 1/3 of your crushed coral at a time and replace it with well washed dry sand waiting a week between removals. You will not start a new cycle using this method.

 

[ImTacticool]

I will second what thegrun and mcgyvr are saying. Take your time, patience is a virtue in this hobby.

 

[mcowan]

Great I will start today. Thanks so much!

 

[mcowan]

Another question - when I moved one of my live rocks a bristleworm came out - it's at least 6 inches long if not longer - should I remove it???? I heard they can be beneficial as decomposers but that thing is huge!