Introducing fish to perculas

[leezard]

My husband and I are new "reef" keepers.

Ok. No reef, yet. I just like to say it. One day, one day.

We have a twenty gallon aquarium with about 11 snails, 5 hermit crabs, 2 conches and 2 perculas, who are apparently determining who is male and female.

We were told by Jason at AI that they tend to reach sexual maturity at around 3 years, and have a tendency to become extremely aggressive (as he pointed out the scars on his knuckles from bites).

In discussing this, I was told that purple firefish and the orchid dottyback should get along fine as long as there are plenty of hiding spots. That there are, since we have much of the branching live rock with lots of crevices.

The two spot goby, however, may not get along so well.

We're trying to determine what else to put into the tank so it a relatively peaceful community, and in what order.

My thoughts went to the goby -- if we were to add him to the tank before the percs showed signs of aggression, would this be a likely safe scenario, or would he likely be eaten as soon as they matured since he'd be unaccustomed to aggressive fish in the tank?

Or, if we were to wait until the percs reached maturity and add him to the tank at that point, would he be MORE likely to survive?

I realize that there are ALWAYS chances of fish dying. I just want to minimize these chances!!

Also, the pH dropped from about 8.3 to 7.4 in a matter of about two days. The staff at AI could only think that someone was possibly spawning. Nothing in the tank has changed, my last water change was last Friday, it does not sit in front of the window, no windows were open (I'd be nuts to do that!!).... I thought it odd that it dropped so low. Any ideas?

[Pier Pressure]

You should maybe get rid of the conches as your tank is too small to give them enough to eat for very long. They will starve to death eventually.

And you are looking at putting five fish into a twenty gallon? That seems pretty high to me. I have five fish in a 28 gallon and would only go with three or four if I was to do it again. One is a yellow clown goby so I do not really count him as he is so small. Bioload is extremely high regardless and we do not dare miss a weekly water change of about 20%.

I have had no trouble with my clowns (one real and one false perc) being agressive to any other fish.

No idea about your pH so hopefully one of the more experienced members will chime in.

[leezard]

You should maybe get rid of the conches as your tank is too small to give them enough to eat for very long.

Hm. Well. They said it should be fine.... and if not, apparently I can feed them seaweed wrapped on one of the rocks on the bottom?

And you are looking at putting five fish into a twenty gallon?

We were at first, but have been told to back off a little on the bioload. We're more just deciding between these what we want the most-- and if the twospot will be a huge problem, he'll probably be the first off our list.

Bioload is extremely high regardless and we do not dare miss a weekly water change of about 20%.

I sticking with about 10% per week... so far has worked out, but I'm sure that may change once we add more fish!

[Pier Pressure]

Well I am no expert by any means. You may want to google conches and see what it says online. Sadly sometimes people will mislead you at an lfs just to make the sale, or because they themselves do not know any better. Actually you might be okay with the supplemental feedings. I was just told my tank was too small for a conch.

[leezard]

A google search comes up with pretty much the same info, but alot of it is vague. I know another girl who has one in her... I think it's a 10g nano, and it's doing swell. These guys aren't supposed to get big, though -- yet there are varieties of conches that do get much bigger. Maybe those are the ones you were told about?

These guys didn't make money off of the conches, though -- there was a mistake in shipment and they got too many of them. I paid $4 each.

[Pier Pressure]

You should be okay with the small ones but I have read even in a big tank they do better with supplemental feedings. So as long as you are supplementing - they should be just fine. I had not realized they were the dwarfy kind!

[naesco]

Too many snails and no room for conchs. Return most of them to the LFS for a credit. By adding algae to your tank you are simply adding to the bioload.

Sorry to say but the likely cause of the ph spike is the death of one or more of them to starvation. Have you checked your ammonia? Another cause would be insufficient current for oxygen exchange.

You have a nano tank which is what I have at the office. I have two false percs and would not add anything else.

You are on the right track to avoid aggressive fish. Avoid the dottyback for that reason. Avoid the firefish unless you have a covered tank and avoid the 2spot as they have a very poor survival record.
Consider a yellow goby or a passive small fish with a good survival rate.
Thanks for asking for advice before you buy.
Good Luck