Which fish to add

[Jeanette]

I have a 20gallon long frag tank. It is packed with corals, mainly SPS corals, some LPS, and a few zoas. I have a very difficult time keeping nutrients in the tank. Currently I have a pair of gladiator clowns in the tank. They mainly reside in one corner and host on a small anemone there. I would like to add another fish or two. Fish I am considering are a royal gramma, tailspot blenny, or six line wrasse. I wanted a green clown goby, but cannot find one at the moment. There is no sand bed, and only a minimum of rock, but with all of the coral frags, I think that provides 'hiding' places. What fish (or 2) would you recommend???

 

[Joj]

All those you mentioned are ones i woild get myself for a 20g long. I never had issues with a 6line wrasse contrary to others saying they are vicious (have 4-5 over time).

 

[1112-425XL]

Can't go wrong with Tailspot Blenny

 

[mbuxton]

Just don't be tempted to buy an Orchid Dottyback. Look nice and are cheap but mine was a horrible, evil little creature who over a span of a few years killed several of my fish including a wrasse and a blenny. It had no issues taking on fish 4x its size.

 

[Jeanette]

Thanks for the replies.

 

[Tahoe61]

Rather than forgo possible aggression from established clownfish and possible introduction of disease brought in by a new fish, I would simply dose nitrates and phosphates.
A Royal Gramma would be my choice if you add another fish.

 

[Gumbies R Us]

I am partial towards Yellow Watchman Gobies so they would get my pick!

 

[kfries]

Royal gramma adds nice color and they are not going to bother anything. I had a pair in a 20 with some clowns and they were all good citizens.

 

[Chessmanmark]

Those fish are all so different.
What are you looking for?

The wrasse will add the most activity.
The Gramma is colorful, but less of an open swimmer until it establishes itself and you add another fish. Them it gets all worked up.
The Blenny adds utility and a huge personality.

So what do you want from your next fish?

 

[Jeanette]

Increased bio-load. I've had all 3 fish before in other tanks, and like all 3. My last royal gramma was not a model citizen (in a 75 gal tank), so that concerns me.

 

[Puggz]

Not on your list but a small Tomini Tang would be nice. They just swim back and forth, picking at GHA. Plus, they are pretty!

 

[Chessmanmark]

Increased bio-load. I've had all 3 fish before in other tanks, and like all 3. My last royal gramma was not a model citizen (in a 75 gal tank), so that concerns me.

You said that this is a frag tank, so you might want to think about utility. The 6 line will eat all kinds of pests while the Blenny will help with algae control.

As far as nutrients are concerned it’s easy enough to do a 25% water change with a 5 gallon bucket.

 

[Chessmanmark]

Not on your list but a small Tomini Tang would be nice. They just swim back and forth, picking at GHA. Plus, they are pretty!

This is a 20 gallon tank.

 

[Puggz]

This is a 20 gallon tank.

I stand corrected! My LFS has at least 1 small TT in each of their frag tanks is where I got the idea from. Albiet they are larger than 20 gal..

 

[BryanM]

I cannot be certain, but I see posts often that end up being flatworms, 6 lines eat flatworms, I have one, and knock on wood, I've yet to see any flatworms in my tank.

For the utility I would vote for the wrasse.