Frag Tank: Sand or BB ?

Pufferpunk · Oct 20, 2008

It's time I broke down & finally set up a frag tank. I will be using my 15g Mantis shrimp tank. (I hope he doesn't mind being moved to the big fuge--plenty of rubble to play with in there for him.) The tank has a HOB Aquaclear filter, filled with rubble for a mini-fuge & a Backpac skimmer, in addition to a 3" sandbed with medium-grade sand in there (easier for the Mantis to move around). I want this tank to stay as stable as possible (being so small). The HOB & skimmer are my only flow. Do I need more flow in there? I don't want the frags blowing around.

Once daily dosing of vitamin C keeps the nitrate <10, even with the heavy-eating Mantis in there, so I think I should be able to keep parameters stable (at least nitrtrate) with the VC. I already do top-offs every day or even 2x/day, if I remember. Should I leave the sand in there for better stability? Or do most folks have BB frag tanks?

Also, what about mixing corals in such a small tank? I want things to heal well & be far enough away from each other not to sting their neighbors. I forgot about my chalice frags being so close to the montis on my small frag rack & one very expensive monti got killed. I will be making a 3-tiered frag rack, keeping the leathers on the bottom (I plan on fragging up my huge green-polyped toadstool & also a yellow one), LPS in the middle & SPS & zoas on top. Or maybe I should leave some room on the sandbed for the stinging LPS & put zoas in the middle? Will adding Purigen in the HOB filter be enough to handle the chemical warfare in a small tank? It's worked great so far in my larger tanks.

ahayes13 · Oct 20, 2008

persoanally i would go with a sand bed. i think with a smaller tank it helps keep a more natural biological balance. however i only have an 1 1/2 inch sand bed. keeps things in balance but wont hold as much gunk :).
you may want a lil more flow though. i wouldnt go too much though, like you said you dont want things being blown to bits in there. i have a 10gal frag tank and i have a small wavemaker for a 20 gallon (cheapy one) and it seems to be doing the job.

Pufferpunk · Oct 20, 2008

I thnk if I add anything, it would be a nano Korilia.

revhtree · Oct 20, 2008

BB for sure! Ran it both ways and BB is better IMO.

Reef Pets · Oct 21, 2008

I agree with Rev. BB all the way. Throughout the many years of reef keeping I have never had sand in a tank. Sand does look great but I see many down falls with having it. Of course this is only my opinion.

Pufferpunk · Oct 21, 2008

I don't like BB for my main reef tanks but I'm not sure about the frag tank. I do think it might keep a tank as small as 15g more stable. Also, I can "plant" the LPS in the sand, away from doing damage to the other frags with their sweepers.

iani · Oct 21, 2008

Your idea to "plant" the pieces in the sand is a bad idea. If they are sensitive pieces and sand gets on them, it could cause tissue recession and die.

Russellaqua · Oct 21, 2008

My biggest concern with a BB is if a frag falls it's likely to frag again if it's a thin branched coral. I always used a sand bed for the extra biofilter/diversity, and to protect corals.

revhtree · Oct 21, 2008

I like sand for my main tank, but not for my frag tank.

cparka23 · Oct 21, 2008

I second the point made by ianiwane. You don't want freshly cut frags to have sand on their exposed wounds. That's an infection waiting to happen.

If you're really wanting a sandbed for biological filtration, I'd consider a remote DSB.

igot2gats · Oct 21, 2008

go BB - more flow available

Pufferpunk · Oct 21, 2008

Lots of good opinions here, thanks.

iani · Oct 21, 2008

Russellaqua said:
My biggest concern with a BB is if a frag falls it's likely to frag again if it's a thin branched coral. I always used a sand bed for the extra biofilter/diversity, and to protect corals.

If a frag falls and you have sand it may get burried.

JGoslee · Oct 21, 2008

Is this going to be a true frag tank or a small reef tank that holds frags? If it's a true frag tank then I would go bare bottom and wouldn't add anything except frag racks and flow. If your looking to have a small tank that will primarily hold frags but also house a small fish and a cleanup crew then by all means add some sand if you think it will look better.

Weekly water changes and a dosing plan is all you need for stability.

Pufferpunk · Oct 21, 2008

It's just a tank to heal & sell frags out of. I do think I need some kind of crew in there, as some of my corals will need feeding.

oceanparadise1 · Oct 21, 2008

bb all the way for a frag tank! and they should never fall if you have the right racks in there. i am picking up a 65 today that is going to be frag tank but im going to make a couple levels with egg crate so i never have to worry about them falling