adding fish to tank and max number in tank

homer_marge · 02-06-2007, 10:23 AM

Hi again everybody,

Just wanted to get some opinions out there about how
frequent fish can be added to a tank? And what is the
max number a tank can hold?

We have a 75 gallon bow front tank. Right now we have
a brittle star, 2 emerald crabs, 1 yellow tang, 2 clownfish
and 10 astrae snails. We read that it's 2 inches per gallon.
So right now including the inverts there are 16 "things" in the tank. For the rule of thumb, are inverts included?

And as for the frequency of adding new fish...we bought the clowns a week ago...is it OK to add more fish this weekend? What's the wait time or is there one?

thanks for all your great advice

homer & marge
(lots of questions this morning!)

Chitown1 · 02-06-2007, 11:19 AM

2" per gallon would be well overstocked, the only number I have ever heard of is 1" per 5 gallons, and that needs to be figured at mature sizes not the size purchased. A marron clown for example are generally purchased at approx. 2" but when mature will grow to a size of 6", however these stocking limits are based on when there is a power outage or another occurace where as the water can not be propely oxygenated, not while the aystem is running so if you have a sufficent battery back up or a back up generator you can safely stock higher amounts. As for adding livestock, I generally wait 4-6 weeks in between stocking and check the water parameters to ensure the system has re-stabalized.

rayjay · 02-06-2007, 11:56 AM

I don't know where you heard the 2" bit, but it's most certainly wrong.
There should be no definite inches per gallon rule as too many variables come into play but the most common rules I come across are 1" per 10g for reef and 1" per 5g for fish only, providing the filtration can handle it.
You could have a lot of rock in the tank for great filtration, but more rock means less free swim space and that will also dictacte what fish you can put in the tank.
With a reef tank of 75g you shouldn't have any more than about 5 to 7 fish at most, depending on the relative full grown size each will get to. In other words, don't put 7 med. sized fish in it and don't stock it based on their present size unless they are fully grown when you get them.
Fish selection, and combinations of fish can drastically affect what you can have in a tank. Some fish can only get along together if the tank is large, some fish are big polluters and require a lot of filtration just for themselves.
Also, the amount of biological filtration for the tank will have a bearing. A mature tank can handle increased bioloading sooner than a newer tank.
As for how fast to be able to add fish, that too is a variable because it depends on how fast each tank is capable of increasing it's biological bacteria to handle the load. Obviously a mature tank can do it faster than a newer tank can.
Another problem you will most likely encounter is hostility towards newcomers, as the longer that tang has to establish territory, the less likely he is to accept new tank mates, especially in that small of a tank.
While I don't like "rule of thumb", I personally wouldn't add more than one fish a month to my tanks, unless I was adding a mated pair of something.
Inverts would normally not be included in the stocking density.
I would recommend at this point to stop, and do a lot more research into fish densities and compatabilities and fish habits. (like are they free swimming or spot dwellers, or rock dwellers)
Many of us found the hard way that in this hobby, nothing good happens in a hurry, but the bad things sure do.

rayjay · 02-06-2007, 11:58 AM

Quote:

Originally Posted by Chitown1

the only number I have ever heard of is 5" per gallon

I think maybe you meant 1" per 5 gallons?

Chitown1 · 02-06-2007, 12:10 PM

Quote:

Originally Posted by rayjay

I think maybe you meant 1" per 5 gallons?

gotta love tyepo's.

homer_marge · 02-06-2007, 01:35 PM

yes...typo, there..sorry about that guys!!

great advice from both of you, much appreciated.
it's always such a hard thing when you want to get things
going, but need to wait....patience is such a virtue!

thanks again!