DSB or no DSB?

[darknes]

I've been battling nitrate and phosphate problems for a while now, and I believe it's due to my crushed coral substrate. It worked fine for a while, but now it's starting to cause problems since I cannot fit a vacuum in many spots to clean it out.
I've decided to try replacing it by taking everything out and into tubs, and then cleaning the bottom and adding sand. This will be a good time to change my rockwork since it was originally setup to be a fish-only tank, and I upgraded to a reef, and the rockwork makes it hard to place corals.
I wanted to know if I could get some opinions on whether to go with a DSB, or just an inch or two of sand. Could I get your experiences, and how much maintenence either would be? This is a 29 gallon reef tank, with no refugium or sump. I eventually plan to add a rufugium in the future, but not for a while.
I know I don't want a bare-bottom, so I don't need suggestions for that.
Thanks for any help and comments.

 

[duke13]

DSB does have its benefits. However, a 29 gal isn't that tall and a DSB will take away from your 'viewing' space. DSB are great if you're going to have a burrowing fish like a Yellowhead Jawfish. I have just a 2-3 inch sandbed and I do fine. Maintenance wise, it would be the same either way - which is practically none.
Do you currently have fish in there? Adding a full sandbed will probably cause another cycle in your tank. You may want to consider adding your sand gradually, like a cup or two every water change.

 

[bobothewizard]

Remove the CC and put at least a 3 inch sandbed in there.

 

[symon]

I agree with Duke, you are going to want to go slow with this, lots of new sand at once , i would think would cause tank to cycle. I have a 2-3 in CC substrate, i don't have problems, I wonder if you open up the LR to allow flow throughout , will it help, change the pad on your biowheel, water changes?
Rearrange your LR to allow you to vac better and water changes would be my 1st approach, but that's just me.

 

[darknes]

I do have fish and corals in the tank. It's been running about 16 months now, with very few problems. I've been wanting to deal with this problem before it gets out of hand.
The way I plan to change, is to remove everything except the substrate (keeping all the water). Then, clean out the bottom, add the new sand (seeded with live sand), and slowly add the old water without stirring up the sand too much. Then, I'll rearrange my live rock, and add my corals and fish and inverts.
I don't think it should cause a cycle. I'll be seeding it with some of my old substrate. This is the way I read here on this site that works best.

Symon, how long have you had your CC? Mine started to cause increased nitrates and phosphates about 4 months ago. The general consensus I've read most everywhere is that eventually, CC will cause problems. Mine probably started sooner since I very seldom could vacuum it, and I probably overfeed my fish.

 

[darknes]

Do you think it will cause a cycle if I did this?
I can't think of any other way to do it.