Fish Bioload Thread

[Sk8r]

Damsel and clowns are about identical, depending on size of species, granted they're roughly the same fish, same behaviors.

Blennies and gobies are about the same as each other, except that one will process film algae and the other will process sand gunk---weight for weight, they're both an asset if they leave what you value alone. They tend to process waste pretty well. Toss jawfish into that pile. Some gobies like the dragon really move sand, but others like the yellow watchman, same size and general look, are much more sedate. In all, they're more processors than outputters if they're backed by a good complement of bristleworms.

 

[mattsilvester]

As a note aside, in my experience you will reach the territorial capacity long before you reach the biological.

Also, nothing is worse that uneaten food and other decaying matter - so some fish as Sk8r points out will probably be a net consumer rather than net contributor of the "bio-load" - or at the very least "cost neutral".

In terms of stocking rates; I think that the 1" per 5 gal rule is a good guide, but no one will argue that a 6" tang or angel cannot be compared with 3 x chromis or clownfish; both in terms of bioload capacity and overall territorial or "living space" capacity.

To that end, I stick with some rules of thumb such as:
- typically, "medium" and "large" fish such as tangs and angels will reach about 60% their size in the home aquarium and then spend years trying to do the remaining 40%. So a fish that will get 8-12" maximum size will probably get to about 6-8" in the some aquarium, max size 6-8 probably about 4-6" etc.

- the 5 gal rule applies to medium sized fish i.e. those that will "probably" reach about 4-6".

- for bigger or smaller fish, the 5 gal rule should probably be adjusted up or down by about 50% for "living space"i.e. small fish like chromis can probably be allocated 1" per 2-3 gallons while bigger fish like angels and large tangs probably about 1" per 7-8 gallons.

- for bio-load, I think similarly those that fall into the small catagory are probably about 50%, but those that are big should be doubled (+100%).

As with anything, all the above should be taken with a grain of salt and there are so many additional factors such as:
- what is fed, in what quantity, when and how often (small feedings multiple times per day, or once a day gorging).
- what is the shape of the tank (arguably, deep tanks provide lots of volume but less space).
- the mix of fish; a good mix whereby some fish will literally eat the poop of others, and not compete for territory will be more efficient in terms of stocking capacity.