replacing crushed coral advise

[littlemannin]

I am thinking of changing my crushed coral with sand. I have some questions about it. Can I do this with all my critters in the tank or can I do a little at a time? I want to change because I think I may have a problem with phosphate a nitrate leaching out. The reason I think this is that I always have green hair algae growing in one spot on the sand bed. This crushed coral is old. I am guessing about 7 years old. Any input would be excellent. Also if anyone thinks I may be going down the wrong path please chime in! Tank specs: 55 gallon I use RO water phosban reactor, tests always read 0 in PO4 and NO3 my skimmer is Aqua C remora pro with mag3, big and ugly but skims very well, livestock is 1 Coral beauty 1 lawn mower blenny 1 cleaner shrimp 1 peppermint shrimp about 10 hermits only one of which is a scarlet the others are blue leg and the occasional snail and a mushroom. I feed about every other day alternating between About 1/4 of a frozen brine shrimp cube and 1/2 pinch of Tetra color marine flakes. The lights are on for 8 1/2 hours a day and they are 130 watt 50/50 compact fluorescent and a rena xp3 canister with no sponges only carbon.

 

[alan214]

I would say that if the CC is not heavily packed down, that you could try to syphon out a bit at a time. I suspect though that as old this CC is that you won't be able to get off that easy.

I would suggest getting a Rubbermaind tub as a temp home for your tank inhabitants and then go after removing the CC. The whole process probably wouldn't take more than a weekend. I'd get the tub with a powerhead in it and start transferring water. As the tank gets empty, net the fish and inverts. Put in a piece of LR or two for them to hide under.

Leave the rest of the tank alone if you can while removing the CC. Otherwise, you may want to consider getting some rinsing buckets setup to swish off of the 7 years of detritus they'll have.

Once that's all done, I'd let the tank sit at least overnight before putting the fish and inverts back. Run your cannister during that time.

 

[littlemannin]

Thanks for the advice. Do you think removing the crushed coral might release gas pockets while removing it? I have about 100# of live rock so I think most of that will have to be moved first. Yikes this sounds like a job! What do you think of the PO4 and NO3 being stuck in the crushed coral? Does this happen?

 

[alan214]

I have heard of that happening. The courseness off the CC can create some significant pockets for NO3 and PO4 to build up.

You have a pretty big job there but at least you won't have much of a cycle, etc. to worry about. I'd also get a fresh batch of RO/DI water ready, too, just in case. Good luck!

 

[littlemannin]

Any advice on what kind of sand to use? and how deep while i'm at it.

 

[jbittner]

Have you considered leaving it bare bottom?? When I changed out my CC I siphoned out a little with every weekly water change. I do not have near the amout of rock you have though. I have about 70 lbs of figi in my 55. I also left it BB and love it.

 

[alan214]

<a href=showthread.php?s=&postid=9205943#post9205943 target=_blank>Originally posted</a> by littlemannin
Any advice on what kind of sand to use? and how deep while i'm at it.

I use CaribSea Arag-Alive (Grade 1-2mm) in my 92G. I'm not sure how much you would need but I recommend a depth of about 2 inches (personal preference). You may want to go at least twice that for a DSB.

 

[littlemannin]

I thought of running a dsb but I don’t think I would like seeing all that sand at the bottom of the tank. And for what its worth my girlfriend freaks out at all the "bugs" in my tank as it is (I don't think she looks at the big picture). If she were to see a bristle worm I may have to hang out at a bar to find a new girlfriend! I was also thinking of about 2 inches... What the heck... I will give it a try. Poor fish!