Crushed coral vs Live sand input

[Jcearl]

Hey everyone i just wanted to get some opinions on my tank- I have a 140 gallon setup with a 55 gallon sump, the tank has been running for almost 4 years now and my fish are great but when i get corals they dont seem to do as well, they tend to die. I do 25% water changes every 3 weeks but i currently have a crushed coral as my base and it is giving me nitrate spikes and collects a lot of detritus i have to keep my power heads on full blast to keep it from settling on the bottom, i have about 300 lbs of live rock in the tank to there are a lot of places for it to settle. But keeping like that also hurts my corals keeping them on that high i have 1 MP40, RW-20, and a WP-40, my return is a speed wave DC-10000 which is doing about 1800 gph at the current height. so my thought is i want to go to a deep sand bed and remove most if not all of my crushed coral. my questions are 1. how to i go about doing this? 2. will removing all of the crushed coral create a huge spike in my tank and kill all my fish? 3. will adding the sand be bad for my tank in the beginning and how bad? thanks everyone for your responses and feed back in advance.

 

[TJ's Reef]

I successfully blended coral sand into the crushed coral bed many years ago when transitioning over. The smaller sand particles filling the gaps. I only had a somewhat shallow crushed coral base though of around an inch so worked very well. Currently and for past 15 or so years have ended up adding at least some amount of larger material in the high flow areas to keep it in place. Having a decent sand based CUC will help immensely with detritus buildup as well ie; larger or numerous Nassarius/Cerith Snails, Sand Sifting Stars, Cucumbers etc...


Cheers, Todd

 

[moulton712]

It's the detritus. Either crushed coral or sand is fine. If I was in your position I'd take all your substrate out and add new.

 

[Jcearl]

would that be bad for my tank

 

[shallowreefer]

Build an algae turf scrubber and you won't have to worry about nitrates......not one bit

 

[jdl513]

Unless that rock is unusually dense 300 lbs sounds like a lot for a 140 gallon.
You might want to consider removing a few of the less desirable pieces to open things up a little.

This would help with circulation and make it easier for you to remove detritus.