Flow rate through sump?

[livingart]

your thoughts on flow rate of water through a sump?

slow to give bacteria longer to work or fast to polish water better?

[kiwiplymouth]

I would say that the answer is dependant on the volume of biological media thats in the sump

[Cricketman]

Size of tank, stocking, media, and everything else will affect it. I'd be tempted to say head towards the faster end of the scale, but not so fast as to cause mass disurbance. the bacteria will scavenge rather quickly, so I dont think that there would be much problem.

Look at fluidised bed filters. Fast water rate and high disturbance, and they are effective.

[David R]

I'd say with a well stocked tank you'd want 6-10 times turnover per hour, and a sump sized appropriately for a balance of the two factors you mention. The sump I'm designing for my next tank (on that topic did you get my PM's Mark?) is going to try to cover both by having the above-water media fed by its own pump separate to the return pump and independant of the flow in/out of the sump.

[livingart]

about 20+ ys ago :oops:

i first built a sump as the bigger canister filters on the market had to be imported and were very expensive

built a few in drums then first glass one one was an old 3 foot tank with plenty of baffles and full of pumice, from large to smaller as it ran through the filter

had a low flow rate pump set up on it

tank had onder gravel filter plates, lots of plants and 8 large discus

tank ran perfecly no problems

i hve been reading a few articles on different bacterias present in tanks and they optimum they work at

i too want to build a sump incorporating both aerobic and anaerobic components

been contemplating potting a deep gravel bed in to see how it functions

[spoon]

could you grow terestial plants in a deep gravel bed like a hydro set up to further clean the water?

[livingart]

that would be a part of the equation

[Jennifer]

I could be wrong but I tend to think of fast flow as better access of dissolved oxygen to the biological media (kinda like blood flow through the body) but if you have other means for oxygenation (e.g. wet dry) that may not be such an issue. Still, if your media are in an enclosed area, I wouldn't think the bacteria would be able to effectively colonise without access to good oxygen levels.

[henward]

its hard to say.

but ... if you have massive massive amoutns of bio media, you can get away with slow.

if you dont, fast is the key.

but you need to also ensure you have enough turnover to turnover particulates.

Unless thats not your main concern.

I say, BOTH.

huge bio media, and fast:D

taht way you cant go wrong!

bacteria grow surprisingly fast in my experience, you just have to make sure you give them the right media to live on.

i also have all the time, redundant bio media spares. any point in time, i can set up a 2 fluval canisters wtih fully seasoned bio media....seasoning is pepper, sumac and a little bit of curry powder..

oops sorry typo, im also typing at a cooking forum 8)

no, anyways, back on track, as i said above

lots of media, lots of flow, you cant go wrong:D

[David R]

but ... if you have massive massive amoutns of bio media, you can get away with slow.

if you dont, fast is the key.

Don't you mean the other way around? What counts is the exposure the water has to the bacteria living on the media that break down the waste, if the flow is too fast the water won't be exposed for long enough for the bacteria to do their thing, and if its too slow the volume of the tank won't be turned over enough for them to make a difference. If you have more media you could have faster flow as there would be more bacteria to convert the waste quicker. Fast flow + a small volume of media would = very little time for the waste to break down.

I think...

[livingart]

you think right in my opinion

[alanmin4304]

Never had anything to do with a sump but have been invoved with using reed beds to clean up septic tank effluent before discharge and the plants that were effective were limited. I think the plant of choice was a noxious weed which requires the consent of Maf. This was being done to strip nutrient but it also brings about a massive reduction in bacteria. The bacteria are trapped in the root zone and if you cultured the right bacteria it might do what you want.

[livingart]

do you know if they trialled watercress alan?

TLC have some good bacterias for this

[henward]

mmm

perhaps, to me, i think having both is the key lol

large amoutns of media and flow.

you can compensate wtih flow rate to have bacteria do their job if you hvae high flow, the repitition compensates i think

[alanmin4304]

Not sure what they tried but I know it was a reed that was used. The bacteria were atracted to the root zone and retained so it was a side reaction to the nutrient stripping. It was done at Lincoln university some years ago. I will see if anyone involved is still about.

[Morcs]

You could somehow run two different systems within the same sump? one for high flow, one for slower flow, for the reasons mentioned above.

Juwel tanks use this method in their internal canisters - the top section is all about mechanical and good turnover, whearas the bottom section is much lower flow for bio.

[livingart]

yes morcs that is what davidr is going to set up i think

[henward]

thats the system i have.

i have a main sump wit a tower that was filte wool

and a scondary tower that just does the water filtration, no filterwool,

works well.

[Morcs]

I should read posts a bit better :oops:

[David R]

yes morcs that is what davidr is going to set up i think

Thinking about it anyway. Henwards system is good, the only think I'd change if I was making it fron scratch is that I'd make the tower taller so the water takes longer to flow over the media.

I'm also planning on having a chamber to let the muck settle out before the mechanical filtration.