stocked vs. overstocked

[Johny]

I was hoping some of you can help me get a better feel for how you determine when a tank crosses the "line" and becomes over stocked?

I was first told (at petsmart) "1in of fish per 1 gallon of water". I have since seen lots of people say that is not the way to do it. I have seen a few people comment that certain fish have high/low bioloads.

So how did/do you know when you are well stocked vs. over stocked?

 

[jetajockey]

there are a lot of factors in play. The inch/gallon rule is a decent basic guideline but it does have many flaws. Example, you wouldn't want to put a 10" oscar in a 10 gallon tank, even though the inch/gallon rule seems to work.

Also, fish aggression/nature is a trait that helps determine stocking amounts.

One thing I go by is just visualizing what a tank will look like with a proposed stocking plan. This is easier if you've looked at lots and lots of tanks with different stock, but its still a bit of an exercise for the mind. Another example, several different schooling groups in a smaller tank looks hectic/chaotic, so it works best when the variance of species is limited even if they have room bioload-wise.

The other thing is stocking for the adult size of the fish. Some fish take a very long time to grow, and people often use the excuse 'well he's still small' or 'fish grow to the size of their tank', and that messes up stocking plans because they really should be based on a long term plan for a tank.

Finally, factoring in what species are compatible with one another, and the level of activity that the proposed species has. Some fish are slow and don't really do a lot of swimming, and work better in smaller tanks than others that are fast and are constantly zooming back and forth.

 

[allaboutfish]

also the filter plays alot in the role of stocking. if you have double the filteration your tank needs you can have more of those high bioload fish.

 

[Johny]

Thank you so much for the wonderful replies! I tried similar questions on a different forum but the members there weren't as friendly.

Where can I learn what fish have high and low bioloads?

 

[jcolon]

Thank you so much for the wonderful replies! I tried similar questions on a different forum but the members there weren't as friendly.

Where can I learn what fish have high and low bioloads?

Start with the max size the fish will grow. From there based on tank size
And filtration, you'll get an idea of your stock size. fish w/ max size of 3 inches will generally have lower bio-load than 4+.

Goldfish are an exception. The have huge bioloads so you need
20 gallon for the first fancy goldfish 10 gal for each additional.
Forget common or comets.. They need ponds!