Convert FO w/ CC to FOWLR w/ sand. HELP

**siestajen** · 10-02-2011, 02:18 PM

Hello. This is my first post. I've had a FO with crushed coral 55 gal for 9 months now. The only fish I have are a puffer (burrfish) and an engineer goby (who lives in a PVC tube). My nitrates are high, but all other levels are normal. I want to get rid of all/most of the crushed coral, and add sand and live rock for better filtration, so I can add more fish later. How do I go about this? This is my first attempt at keeping a saltwater tank. I kinda rushed into it without much patience and research. I'm learning as I go and am ready to do this right!

1. Do I have to remove my fish before I make the transition? Or can they stay in the tank?
2. Should I leave some of the CC in the bottom and add sand on top?
3. Do I add the sand and LR at the same time, or one before the other?
4. Will my tank need to cycle?

Any help would be much appreciated :)

**Cliff** · 10-02-2011, 02:23 PM

You could try adding some dry rock first and allowing it to become seeded and become live over time (about 4 to 5 months). About 50 to 70 lbs of good quality rock would be best. Adding live rock would likely cause a spike and harm your fish so you might want to aviod that. Dry rock is also a lot cheaper.

Once the rock becomes live, you could change your substrate

Have you red the stickies here yet ?

Edit: Sorry, I don't think I helped with all of your questions. Some additional info below

1. Do I have to remove my fish before I make the transition? Or can they stay in the tank?. My suggestion: If you add the dry rock in the way I explained above, you should be fine. No need to remove your fish. However, your puffer is likely to get up to 10” in size so once you add rock to your 55 gallon tank, you might have to re-home him

2. Should I leave some of the CC in the bottom and add sand on top? My suggestion: It depends on the look you want If you like the look of both sand and cc, then go for it. Just keep in mind that the mixture might be a little more challenging to clean

3. Do I add the sand and LR at the same time, or one before the other?. My suggestion: I would add dry rock first, let it become live, then change the substrate. You don’t want to remove the Bactria that you have grown in the tank before you have grown some more bacteria on your rock.

4. Will my tank need to cycle? My suggestion: Only if you add live rock. Then you would need to remove the fish and CUC to allow the tank to cycle

**sheamurai** · 10-02-2011, 02:58 PM

+1 to Cliff

If I was going to add LR, I would add it one piece at a time over the course of months - and the only reason I would consider live at all would be for any beneficial hitchhikers you would get.

Dead rock would be faster and not cause any spikes.

I'd also suggest removing the CC before adding your rock. Remove the current substrate, add all the dead rock, then lastly the sand so the rocks won't shift when your critters start moving sand around to suit themselves.

Make sure to have a heated, aerated/flowed container for your fish while you do this - if you're anything like me, rock placement will take you a while, so just a holding tank will cool off quite a bit before you are done.

**siestajen** · 10-02-2011, 03:14 PM

Honestly I'm not opposed to getting rid of my fish. I think the puffer is going to get too big for my tank anyways, and the engineer goby is kinda boring (even though the lady at the fish store said they're "really fun fish"). Again, I didn't really know what I was doing when I started.
I was worried about getting rid of all the CC because I don't want to get rid of ALL of my good bacteria. Is it ok to have a layer of CC on the bottom, then sand on top?

**smaug** · 10-02-2011, 03:30 PM

Yes you can leave the cc and add the sand on top later.make sure to clean the cc pretty well before adding the sand on top or you could get some nasty pockets trapped. I have a mix of cc,aragonite and fine marine sand,it makes for a very stable substrate for future diggers. Dont make a deep sand bed unless you are looking to get fish such as jawfish that want to burrow. Sheamarai suggestion to have the rocks rested against the bottom is a wise thing as well.

**ILuvMyGoldBarb** · 10-03-2011, 01:16 AM

I'd actually go one step further with the rock on the bottom. Something I have found that helps quite a bit is to put some "egg crate" (the kind for lighting) on the bottom of the tank and then place your rock on that and then add your sand. I've found that using the egg crate helps make the rock even more stable, and it doesn't create any pressure points on the glass. Not really a necessity, just something I found useful.