Help me decide...

[BestMomEver]

5 gallons is really small. What we always preach is constant values and that is impossible in a 5 gallon without a heater or chiller and most of all without an ATO.
I believe symbios gobys are a bad example of animals for very small tanks because they normally live in a bit deeper water in nature which has more constant values.
I would only think of animals you normally find in tidal pools. So what kind of fishes do we find in tropical tidal pools?

If it is possible to connect it with water from another tank I would go with sexy shrimps an anemone and a boxer crab (or 2 if I can get a pair) Maybe a Periclemens shrimp and maybe a Neopetrolisthes maculatus. A small hermit or 2. These animals do not stand varying salinity or temperature but are very charming in a tank small enough so You can see them.
And You have fishes in the other tanks...

I have a heater and a Tunze nano ATO. I’ve decided against the shrimp/Goby pair because of their nifty habit of moving things around. I’ve thought of an anemone but I have an anemone/Clown dedicated tank. I’m staying away from hermits because the always kill my snails. But I might get an emerald crab. Good ideas though! Tidal pools are absolutely cool...

 

[BestMomEver]

Hi fin rose goby. Small, beautiful and will not move your sand much at all. You could pair it with a Randalls shrimp. This goby shrimp stays small, moves some sand, but not alot.
Green or yellow clown gobys . Just 1 of the 2 though. Dont try to mix the diff clown gobies in that small of tank.
Red elongate psuedochromis only
gets 2.5 ". Generally non aggressive compared to other psuedos. Psuedo elongatus, much smaller than royal gramma etc. And all wrasses are probably gonna be to confined in that size of aquarium.

A. Blake
ireef2.com

A while back, my LFS had a rose Goby. It was so cool. I almost got it for one of the other tanks. I had a yellow Goby until he perched on top of a power head and got sucked through and out the other side! I looked around for some of the pseudo species but haven’t found one yet. Still looking though.

 

[Jesterrace]

Seriously? Would you really do that? I’ve had breeding colonies of mollies in fresh water tanks and I know they can be acclimated to saltwater, but I’ve never considered doing it.

Got to agree with this. To me putting Mollies in a saltwater tank is kind of like "what's the point?" (ie if you are going to go through the hassle of a saltwater tank then why bother putting in fish that can go in a freshwater tank).

 

[wesman42]

Got to agree with this. To me putting Mollies in a saltwater tank is kind of like "what's the point?" (ie if you are going to go through the hassle of a saltwater tank then why bother putting in fish that can go in a freshwater tank).

Because they're situational. Such as:

1. Testing a tank after fallow period for ich or velvet because Mollies don't have an immune system for marine illness.

2. Using then for algae control. They will eat marine algae like nutso level. Kinda like a tang. Not as useful, but if you have a smaller tank it's worth it.

3. Cycling a tank....not sure why you'd want to use fish anymore...but it's a cheap option.

4. They're cheap guinea pigs in general. Better to use a $2 Molly than a $100 tang.

 

[scardall]

since you have coral in it, no fish at all. Colorful shrimp would be better and will help keep tank cleaner than a fish would. IMO upgrade to 10 g tank. cost minimal.

 

[Jesterrace]

Because they're situational. Such as:

1. Testing a tank after fallow period for ich or velvet because Mollies don't have an immune system for marine illness.

2. Using then for algae control. They will eat marine algae like nutso level. Kinda like a tang. Not as useful, but if you have a smaller tank it's worth it.

3. Cycling a tank....not sure why you'd want to use fish anymore...but it's a cheap option.

4. They're cheap guinea pigs in general. Better to use a $2 Molly than a $100 tang.

True, but we aren't talking about a "test fish" application here, the OP is looking for a centerpiece type fish for his 5 gallon. A Molly doesn't fit that in a saltwater tank IMHO. I would take a tailspot blenny over a molly any day of the week (and it will do a better job at removing algae).

 

[wesman42]

True, but we aren't talking about a "test fish" application here, the OP is looking for a centerpiece type fish for his 5 gallon. A Molly doesn't fit that in a saltwater tank IMHO. I would take a tailspot blenny over a molly any day of the week (and it will do a better job at removing algae).

Yes, I agree with that...but I just wanted to point out they have uses [emoji14]

 

[Jesterrace]

Yes, I agree with that...but I just wanted to point out they have uses [emoji14]

As a cheap test fish it is possible, although they really are better suited to brackish and not full salt. A Damsel is probably the best "test" and long term solution. You can find some for under $10 if they are ordered in bulk from your LFS or on sale from a supplier.