How many fish can be kept per tank?

[meemoo]

I thought there was a rule of thumb of how many inches of fish per gallons?

 

[smcnally]

There is a "rule" but it really doesn't make any sense. Normally they say 1" per 10 gallons, but I don't believe it. I think with some fish that could be right, but others wrong. I think it all depends on the particular fish's bioload, and how much room they need to swim.

 

[jango]

I think it all depends on the particular fish's bioload, and how much room they need to swim.

It depends what you want to keep.

What size tank and what do you want to keep for fish?

 

[~Flighty~]

And what do you want to keep for corals, and what other things will there be that need to eat? Too many variables for a reef tank to have any sort of rule of thumb. I kind of go by how much I need to feed the whole system every day. The anemone alone eats about the equivilant of a bigmac every week.

 

[Mr. Slippery]

The anemone alone eats about the equivilant of a bigmac every week.

Maybe it should go on that show with the guy who ate just mcdonalds everyday. It's cholesterol must be through the roof.

 

[NateHanson]

Probably best to throw out your tank size, and name a couple fish you might like to keep. Then people can advise which ones they think would be a good match, and what a good combination might be.

Number of fish, or inches of fish per gallon is an arbitrary useless measurement in my mind. A 5" bar goby could be one of a couple fish in a 30 gallon tank. But a 5" hippo tang would be a whole bioload-worth for that tank, and because of it's behavior it would only be suitable for a tank at least three times that size, regardless of bioload.

 

[saltwaterB]

Also,you can bend the rules with the right equipment, right size system(overall), and lots of water changes. I would not recommend this for a reef tank though. A psuedo reef, no problem. The problem lies when we start to slack in the maintenance. Thats why I always say pay someone to do your water changes and they get done on time all the time. Actually I am biassed on that one
But I have kept some way overstocked tanks for customers, because that is "what they want" It is all about balancing the nutrients. You need to export at least or more than what is being produced. Achieve this balance by proper volume, filtration, and maintenance and should be successful no matter what you do.
Now the hard part is making sure that all the animals will get along in your mini ocean.

 

[meemoo]

I have a 56g column tank with a hob refugium. Up to date I have 2- clowns, 1- bangaii, 1- scooter blenny and 0 nitrates. I think the refugium with chaeto helps. So I added a 6 line wrasse the other day. That's when I started thinking do I have too much bioload. I thought corals and inverts don't count as bioload, at least that's what I was told by my LFS. I am planning a 30g sump to add soon to increase my water volumn. I have the Aqua C Remora skimmer as well as at least 70lbs LR.

 

[Triggerfish]

i would think that should be fine... nice little setup..keep fish that grow no more than 3".
as always, water quality is one determining factor.

 

[jacqur]

magic corals and inverts

Interesting comment about you LFS telling you that corals and inverts don't count as bio load. I wonder if they have any more of these magical specimens that do not produce waste products. I would be interested in picking up a few.

 

[NateHanson]

I agree that inverts and corals have no significant bioload. They primarily eat what would otherwise decompose and create waste anyways. The bioload that really matters is the organisms you have to feed in your tank. That food is mostly converted to poop. So in a way you can relate bioload of a fish to the amount of food added to the tank for it to eat. Crabs and shrimp that eat dead things, and food that the fish missed and fell to the bottom, don't really add to the bioload because they prevent that extra food from rotting and poluting the water. Yes they excrete waste, but it's a net positive on water quality because it's a fraction of the waste that the decaying food would create. (the rest of the nutrition in the food was used to give the crab energy or converted to crab biomass).

Nate

 

[Triggerfish]

I wonder if they have any more of these magical specimens that do not produce waste products.

i would think most/all corals do not have a digestive system. hence,,whatever they consume is probably retained and used for growth.

 

[NateHanson]

I believe they do have a digestive system similar to echinoderms, anemones, etc, just on a much smaller scale.

They rely on water movement to remove their waste products. My point is not that they don't produce waste products, but that those waste products aren't a net water-quality liability unless you're heavily feeding your corals.

 

[Triggerfish]

yes,,that makes sense. if they grow you would think they must need to 'digest' something...

 

[~Flighty~]

But many of our corals are spot fed and an anemone can eat much more than a large fish can, heck, mine can eat a large fish .