View Full Version : Crushed Coral driving me nuts - any suggestions??

10-09-2003, 10:30 PM

On my LFS's suggestions, I put crushed coral as the substrate in my Cichlid tank. It cycled fishless and I only have just started to add my fish.

Now it appears to have green algea (??) growing on the top of it where there is no shadow from the rocks. I have 2 bristle nosed plecos in the tank, I put one of my SAE's in there the other day but had to take it straight back out as they all "ganged" up on it!! I only vacuum the tank once a week but the discolouration seems to be stuck on. Could maybe some sand go over the top?? Any suggestions would be greatly appreciated. The lights are left on around 12 hours or so a day (thinking of getting a timer...should there only be a set time??).

3 yellow labs, 3 blue haps, 2 plecos currently are in this tank with 1 more of each and 4 peacocks or zebras coming soon.....decisions, decisions...)

Thanks in advance for your help


10-10-2003, 12:28 PM
Don't mean to be a downer, but I'd get rid of the crushed coral..... not good for cichlids as the particles are too sharp..... injuries often occur to the gill membranes, etc. during digging.

Also, algae grows more readily on a light surface than a dark one, but your problem has nothing to do with the makeup of the substrate (other than the light color). Algae comes from two things generally:
1. Too much light
2. Too many excess nutrients (that's the big one; usually nitrate and phosphate are the culprits); lighter feedings and water changes will reduce the nutrient level unless your tap water is high in nitrates.......

10-10-2003, 06:19 PM
Thanks for the reply, I wish I had of asked before buying the stuff, $55.00(au) for 10 kilos. I don't want to take it out and just turf it, is it possible to put 2-3 inchs of sand over the top?? Or will they dig further down... I'll go to the landscape suppliers tomorrow to get sand. If I have to take the coral out, it will just have to go. I am setting up an oscar tank at the moment in my other 55g (just one oscar and a pleco) could the coral go in there?

Thanks again for your help


10-14-2003, 11:03 AM
Oscars are so messy, it's generally best to go with no substrate. If you are concerned about appearance, just use a 1/4" - 1/2" layer of fine gravel. You'll need to be vacuuming the gravel regulary, and the gravel will do better than sand in the Oscar tank.

I'd just ditch the coral in the first tank and get some cheap pool filter sand (coarse grade). No use keeping the coral.... covering it, that is..... if it's just going to cause trouble (yes, they will probably dig down to it).

BTW..... the deal with substrate is generally very shallow (less tha 1/2") or very deep (5" or more in a deep sand bed for a marine tank)........ unless, of course, you are utilizing an undergravel filter.

10-14-2003, 05:11 PM
Thankyou for that. I have the sand, now comes the tedious task of removing the coral....thankfully my hospital tank is free so I can put the cichlids in there while I am removing it.

One question though. The tank has been running for around 6-7 weeks now, do you think that removing all of the substrate will do too much damage to my bacteria??? I have a AQ 500 on the tank that should be well on its way by now biologically....

Thanks Again (I seem to say that alot!!)


10-15-2003, 09:15 AM
You should be O.K......... but pay close attention JIC.

FYI.... the easiest way to get rid of the sand is to siphon it out with a big hose.

10-16-2003, 03:31 PM
12 hours a day is way too long. you should go with 8 you can get a timer at walmart home depot coscto has a digital one for 14 bucks, like chc said you could probably just keep the substrate and starve the algea, you can buy a phosphate sponge at the lfs which will starve the algea or even a uv sterilizer if you want, but if it were me I would probably like the look of the algea covered coral I bet it looks nice and natural.