Fish stocking calculation includes rear chamber/sump area?

BigEZ77

Member
I have a JBJ RL 45 AIO tank, which really fits about 40 gallons when full. I estimate there are roughly 10 gallons in the rear chamber and 30 gallons in the display. Should I calculate my total fish capacity based on the display water volume (30G) or the overall volume (40G)?

Thanks,

Russell
 
It really doesn't work like that in the saltwater world. What works in a tank is based much more on species demand and interaction with other tank mates rather than on amount of fish per water volume.
Lots of people here with years and years of experience are happy to critique and offer suggestions if you post a stocking list, but in terms of numbers or inches of fish, it's more based on swim room (which would mean gallons in your display, not total water volume).
 
For purposes of water chemistry, the support volume counts. But fish have a psychological and social dynamic. Some fish just do not want a rival within say it's 100 gallons and will not tolerate anything in its private space of say 10 gallons. Metabolically, the water might be able to support 10 damsels. But put them all in the tank and carnage results.

Then there are other fish that are so active as to need large tanks, tangs being the best example.

It is probably safest to plan the tank on the display tank volume. The extra volume in refuguia and sumps just keeps the water quality pristine. That does not mean that a certain bloody minded fish will not take it into his head to murder everyone.
 
Thanks for the info. I'm thinking of putting in 8 Green Mandarins...kidding! Right now I have two clowns and would have liked to have a total of 8 fish but I'm thinking that might be a little much now, so perhaps 6. Will be adding one fish per month with some soft corals and LPS in between. Here's the options...

Citrinus Clown Goby
Royal Gramma
Banngai Cardinal
Court Jester Goby
Tanaka Pygmy Wrasse
Helfrichi or exquisite firefish

Will add a screen cover for the last two.
 
Also, does live rock come into effect when calculating water volume? I have about 45 lbs in the tank which obviously has displaced quite a bit of water.
 
The ability of any tank to handle a particular fish load is twofold. First how well the system can process wastes (not just the conversion of ammonia to nitrates, but the levels of the latter); and second swimming room. Most tanks with even modest amounts of live rock are not deficient in bio filtration capacity. Too much rock means less space and less fish.

IMO, volume for the sake of volume is over rated. Sure, in the case of certain problems, greater volume can provide a dilution effect and be useful; but it doesn't end up being all that much help in most cases unless it's a bigger display. Bolting on all sorts of extra sumps is a big old waste of time.
 
Thanks for the info. I'm thinking of putting in 8 Green Mandarins...kidding! Right now I have two clowns and would have liked to have a total of 8 fish but I'm thinking that might be a little much now, so perhaps 6. Will be adding one fish per month with some soft corals and LPS in between. Here's the options...

Citrinus Clown Goby
Royal Gramma
Banngai Cardinal
Court Jester Goby
Tanaka Pygmy Wrasse
Helfrichi or exquisite firefish

Will add a screen cover for the last two.

That looks good to me. All peaceful fishes that fit together just fine. Grammas can get cranky, but they are more bark than bite. All good choices though.
 
Back
Top