When do our fishes reach full size?

[pohtr]

Since we need to keep in mind the full grown size of the fishes we choose to put in our tanks, how do you know when they're full grown? Do they keep growing for years and years? The maximum size listed in the various fish descriptions are just that, MAX size and not usually the sizes our little fishes will grow to.

 

[imurnamine]

Hmm... it might just depend on the species of fish.
We need Ophiura!

 

[xdave]

The larger a fishes max size, the longer it takes to reach it. This is a rough guide and will vary by species but; if a fishes max size is 1/3 to 1/2 the smallest horizontal tank dimension (in your 90 that would be about 6"-9") they will probably hit 90% of how big they will get in there within a year. A 12" fish will probably hit 9" in a year and maybe 2 or 3 years, if ever, to hit 12". Any fish with a larger max size that that will not do well in a tank with those horizontal dimensions.

 

[pohtr]

So then, what's the best way to calculate how many inches worth of fish your tank can handle? I am currently at 15.3 MAX possible inches worth of fish. I want to add 2 more at MAX 7.9", totalling 23.2MAX inches total. If I go by the 90% then I'm only at 20.88 inches which should be fine considering the extra gallons in the sump.
Or am I obssessing? (not at all unusual for me)

 

[nereef]

inches per gallon isn't what's important.
what is your stock list and how big is the tank?

 

[xdave]

I use 1" per 5 gallons of tank water, no one fish to exceed 50% of the smallest horizontal measurement. I don't count the sump water, it does matter filtration wise but not space wise for the fish.

 

[pohtr]

90 gal w. maybe 90 lbs LR w. about 18 gal in the 30 galsump, maybe half in the fuge which is finally full with macroalgae, LS and LR rubble and teaming with itty bitties.
What I have now is:
one Clark's clown (the biggest at about 4")
one flame angel
one magenta dottyback (pseudochromis porphyreus I think)
one blue-green chromis
one big bubble coral
cleanup crew
I want to add:
one yellow watchman goby
one lawnmower blenny
(preferably at the same time)
then later, if possible maybe a pair of yellow clown gobies

 

[travis89]

The watchman and blenny would be fine, the clown gobies should be also. I have a list comparable to what you have in your tank now in my 46 gal which is half the size and I an planning on adding another one.

 

[pohtr]

Originally Posted by xDave
The larger a fishes max size, the longer it takes to reach it. This is a rough guide and will vary by species but; if a fishes max size is 1/3 to 1/2 the smallest horizontal tank dimension (in your 90 that would be about 6"-9") they will probably hit 90% of how big they will get in there within a year. A 12" fish will probably hit 9" in a year and maybe 2 or 3 years, if ever, to hit 12". Any fish with a larger max size that that will not do well in a tank with those horizontal dimensions.
So then when your fishes are a few years old they're at about full size for whatever tank they have been living in?