I resently built a small internal bio filter out of 4 inch pvc and a powerhead. It was just a cheep build to help out the tank. My question is does flow rate matter fast or slow if it's just bio? I know more water contact with filter media per hour is good but also I know that the slower the flow the more time the water in the filter has contact with the media? So how fast is 2 fast and how slow is to slow.
pump size to flow rates
- Thread starter kyle osowski
- Start date
I used to have charts saved on theoscarspot.com but it seems as if that forum doesn't exist anymore.
Too fast is a rate which rips BB from the media. Too slow is a rate where fish suffer harm from the presence of nitrogen (ammonia, nitrite.)
The calculations of this are far too complex for most people to be worried about.
For example, you would want take into account:
1) temperature and oxygen levels
2) the peak amount of protein fed per volume of water over a 6-8 hour interval (to derive short term ammonia peaks)
3) the amount of ammonia per volume of water over a long term (4 or more days)
4) the pH level
5) the size and efficacy of the bio filter
6) the specific species and it's resistance to nitrogen poisoning, including it's size and age
7) other medical conditions of the inhabitants
8) other mitigating protein reducing conditions (e.g., plants, skimmers, drip or continuous water replacement systems)
On a practical basis, people have kept fish in planted tanks with total turnover rates below 1 gallon per hour. Most tanks are too crowded to permit such low rates. People with relatively large bio loads that feed large amounts of high protein foods infrequently (every few days) are more likely to need rapid turnovers than people with relatively low bio loads that feed small amounts of low protein foods on a daily basis. But still, that's quite a generalization.
The calculations of this are far too complex for most people to be worried about.
For example, you would want take into account:
1) temperature and oxygen levels
2) the peak amount of protein fed per volume of water over a 6-8 hour interval (to derive short term ammonia peaks)
3) the amount of ammonia per volume of water over a long term (4 or more days)
4) the pH level
5) the size and efficacy of the bio filter
6) the specific species and it's resistance to nitrogen poisoning, including it's size and age
7) other medical conditions of the inhabitants
8) other mitigating protein reducing conditions (e.g., plants, skimmers, drip or continuous water replacement systems)
On a practical basis, people have kept fish in planted tanks with total turnover rates below 1 gallon per hour. Most tanks are too crowded to permit such low rates. People with relatively large bio loads that feed large amounts of high protein foods infrequently (every few days) are more likely to need rapid turnovers than people with relatively low bio loads that feed small amounts of low protein foods on a daily basis. But still, that's quite a generalization.
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I don't think your going to get, too much flow with low pressure pumps.
Mostly my fluidzed sand filter, is a very turbulent place.
A new algae growing waterfall scrubber screen, will need the bacteria scraped off, so green algae can get a foot hold.
In a calm area. like on a pumice,and highly pourus filter media, the bacteria will over grow the crevices. That give the huge surface area.
In fact eventually even the insides of the plumbing, will sluf of thin white flakes of bacteria colony, when disturbed.
Mostly my fluidzed sand filter, is a very turbulent place.
A new algae growing waterfall scrubber screen, will need the bacteria scraped off, so green algae can get a foot hold.
In a calm area. like on a pumice,and highly pourus filter media, the bacteria will over grow the crevices. That give the huge surface area.
In fact eventually even the insides of the plumbing, will sluf of thin white flakes of bacteria colony, when disturbed.
Yeah it's complacated and that's about what I seen everywhere but I was thinking more along the lines of water flow per foot of piping or hose to measure how fast the pump flows at the start to how fast the water flow is at the end. I usually would like to see a end result of 200 to 400 gph rate. My powerhead is located just below the surface. Pushes 2 feet down the hose. Into 4 inch pvc that it's 3 feet tall and out the top. I know a 200gph pump will not exit at 200 gph. So what pump size would I need to get a average of 300gph I guess was the question. Pvc consists of 1 box of fluval corse ceramic, 1 box fluval bio rings, and about 125 bio balls.