Does Anybody Really Know The Answer

[red devil]

But...to look at it another way...if a fish normally lives in a lake the turnover rate in the water is virtually nill - it is up to the fish to swim to move to a different place to find cleaner water. In a slow moving stream the turnover is also slow. Gosh, we are spoiling our fish

 

[1boatnut]

I truly understand the media and stocking issues,but I still think there has to be some sort of starting point or "rule of thumb",or else filter manfacturers would just make their filters and not state what size tanks they are good for.

I'll google it

 

[red devil]

Starting point, as was mentioned before, start with one or two fish and add one or two at a time...watch the water parameters and the fishies attitude. The fishies know best about themselves

 

[Marinemom]

For freshwater setups I shoot for somewhere between seven and ten times an hour regardless of the stocking in my tanks. For my saltwater setup I have the water in that tank being turned over 22 times an hour since it is a reef.

Marinemom

 

[cohazard]

But...to look at it another way...if a fish normally lives in a lake the turnover rate in the water is virtually nill - it is up to the fish to swim to move to a different place to find cleaner water. In a slow moving stream the turnover is also slow. Gosh, we are spoiling our fish

Well, most of the tropical fish we keep come from streams/rivers, where the turn over rate is constant fresh/clean water. Even in a slow moving stream, the water is constantly turned over is also constant, the fish never swims in their own waste.

There are some fish that come from stagnant back waters, but the filtration setup on those tanks are usually easy because they don't require huge tanks.

I've never heard of a fish needing to swim around to find clean water, rather they swim around to find food. In nature, the nitrifying bactera, and water purifying aquatic plants are everywhere.

 

[TEL]

I have a 240L tank with a sump and 4 times an hour seems to work fine. I had it going faster but all that did was make it harder for the plants to sit upright and for the smaller fish to swim around without being pushed down the other end.

 

[Viettxboii]

i like to do 10x, but with 2+ filters instead of just one... less deadspots

 

[nickmcmechan]

:iagree:

 

[loaches r cool]

This is one of those 'measurements' in aquaria that are pointless.

I agree as well. So many different factors and so many people set on a number when they apparently have no clue what it actually means.

Flow rate in tank? Flow rate through bio filter? Flow rate through mechanical filter? Some river fish like huge amounts of flow. Some fish would be blown away with lots of flow. Some folks swear anything under 10X turnover and we should be locked up for fish torture yet others often say 2-3X is plenty in a large wet/dry. Or filtration like UV or sand filters also use a much lower flow rate than one would normally think of 'turn over' for the size tank they are on. Got a heavily planted tank? You can have no filter, just some in tank circulation. And then to make matters worse, a lot of folks who insist on a set number are actually way off because there filter isnt anywhere near the flow rate that listed.

Best to ditch the rules of thumb like stocking inch per gallon and X gph of turn over and take every setup uniquely into account.