Frag tank 101, the start of a new journey.

[Jscwerve]

So, I'm going to start up a frag tank very soon, in the next few days actually. I have some plans of what I THINK is supposed to be done, but I'm not sure so I also have many questions.

The tank is small. 21x18x11 (18 gallons). It's my first frag tank, so going small, also need to convince the real boss that having it is a good thing first before going overboard! With that small of a water volume, I think things can get out of hand pretty quickly. I have a 40b sitting around and I figured I'd just use that as a sump. 40ish gallons is much more stable than 18, right? Sump will also have an ATO. Lighting will probably be either and AI Prime or a Kessel if I find a good enough deal.

No, there is no way to tie this into my main display, it is going in a basement utility room.

Here is where I have questions.

1. Biological filtration. Since there is very low bioload, is there much live rock required? Since the tank is only 18 gallons, I don't think it's big enough for any fish. Is a small clean up crew recommended?
2. Skimmer size. Do frag tanks use overly large skimmers? I've not found anything on this subject yet. I can't imagine pulling a ton of skimmate out of a frag only system, but like I said, I have no idea.
3. Light cycle. Longer than a normal reef tank to promote growth?

That's all for now, I'm sure I'll come up with more in the next few days.

 

[Goatonfly]

I don't anything about frag tanks, but why not have a 40g frag tank and a 18g sump? Is there a benefit to doing it the way you proposed? The water volume will be the same either way so water quality should need the same requirements, or I could be completely wrong...haha

 

[Jscwerve]

I don't anything about frag tanks, but why not have a 40g frag tank and a 18g sump? Is there a benefit to doing it the way you proposed? The water volume will be the same either way so water quality should need the same requirements, or I could be completely wrong...haha

The 18 gallon tank is made for frags. Already has an overflow and is drilled. I don't like having a tank without surface skimming so installing an overflow into the glass 40 would be a pain and not cost effective at all. Also the frag tank is only 11.5" deep which puts my arm only getting soaked to the elbow when I'm "playin in the tank"! It will be a relief not to have to put myself in up to my shoulder like my main display! Not to mention the better PAR with the water being shallow.

 

[Goatonfly]

The 18 gallon tank is made for frags. Already has an overflow and is drilled. I don't like having a tank without surface skimming so installing an overflow into the glass 40 would be a pain and not cost effective at all. Also the frag tank is only 11.5" deep which puts my arm only getting soaked to the elbow when I'm "playin in the tank"! It will be a relief not to have to put myself in up to my shoulder like my main display! Not to mention the better PAR with the water being shallow.

Makes sense, thanks for the explanation.

 

[SeattleReefer]

I would use a 4" block of marinepure for biological filtration.

I'm of the opinion that you can always turn off a large skimmer but a small skimmer can't be made bigger. I'm also about to set up a frag only tank and I'll buy the largest skimmer that will fit the sump.

 

[Ron Reefman]

Even with a low bio-load, I'd still go for as big a sump and refugium as you can justify. 'Stuff' still happens in a frag tank and the extra water and filtration can be very useful.

The longer light cycle isn't helpful. The zooxanthellae in the coral only do photosynthesis for 4 to 6 hours and then shut down. The coral polyp itself may get some small benefit from extra hours of light, but not much. Some people have had some success doing a 6 on/6 off cycle twice a day. Given this will not be in a 'regular' living area you might try it. I don't find it necessary. My wife thinks I have people over buying corals too often already, I don't need them to grow faster!

 

[Jscwerve]

Even with a low bio-load, I'd still go for as big a sump and refugium as you can justify. 'Stuff' still happens in a frag tank and the extra water and filtration can be very useful.

The longer light cycle isn't helpful. The zooxanthellae in the coral only do photosynthesis for 4 to 6 hours and then shut down. The coral polyp itself may get some small benefit from extra hours of light, but not much. Some people have had some success doing a 6 on/6 off cycle twice a day. Given this will not be in a 'regular' living area you might try it. I don't find it necessary. My wife thinks I have people over buying corals too often already, I don't need them to grow faster!

That's what I kind of figured anyways, that's why the sump is actually going to be about twice the size of the tank. Picking up yet MORE rock to do just that.

Any input on skimmer size?

 

[Ron Reefman]

Since you won't be feeding the frag tank like you would a reef tank, I think you can go with less skimmer ability. But just like the sump, if you have excess, you can always turn it down.

I can't speak to your situation as I have a 65g shallow reef tank/holding tank that shares the sump/refugium/skimmer with my 25g frag tank. So the sump/refugium is an old 125g tank with a big skimmer.

 

[Wally.B]

Hi There,

are you still doing the Frag tank thing?

I am starting a DIY Frag tank Mini Extreme (since I wan't to leave my two other tanks alone). The more I touch them (dosing, feeding, etc), the more I get into trouble.

I wonder if it's possible to successfully grow frags without have Nutrients from Fish Poop. I have all kinds of Coral foods for my LPS tank. Ton's of left over additives.

Did you get anywhere with this?