steve24cro Posted December 18, 2005 Share Posted December 18, 2005 i also came up with a wacky idea, for large tanks, could you use a large pond filter with pump as a canister filter? Any pros and cons? Ive seen some large pond filters (2 times size of any canister filter) and i was thinking of attaching a pump of around 3000lph or so. Link to comment Share on other sites More sharing options...
wui39 Posted December 18, 2005 Share Posted December 18, 2005 I've done it............... The results are good biological activity, water polishing is not so great. Pond filters are generally designed to keep a large population of bacteria growing, not to get the water ultra clear as an aquarium cannister might. Link to comment Share on other sites More sharing options...
teflon Posted December 18, 2005 Share Posted December 18, 2005 I have heard going way overkill can actually be harmful as becteria wont be allowed to grow? Hope that somehow helps Link to comment Share on other sites More sharing options...
wui39 Posted December 18, 2005 Share Posted December 18, 2005 Bacteria population will depend on the amount of waste product. So low stocking levels will not be helpful to use the pond filter. Link to comment Share on other sites More sharing options...
teflon Posted December 18, 2005 Share Posted December 18, 2005 My whole point was if the water is travelling through the filter media too fast bacteria wont be able to grow as its being pushed through too fast stocking levels have nothing to do with it Link to comment Share on other sites More sharing options...
wui39 Posted December 18, 2005 Share Posted December 18, 2005 hmmmmm intereting point.....maybe i should go turn off my water pump then.....perhaps my pond will do better how do sump people get such good filtration? Link to comment Share on other sites More sharing options...
Ant Posted December 18, 2005 Share Posted December 18, 2005 I think what Teflon is saying has some truth. When working at the LFS we had to tell people not to crank their Otto 1800 lph on full when they are trying to establish the filter. The reason was that it took ages for them to become established. When we told them to slow them down a bit there was no problem what so ever. I experienced this on my own otto filter and two others of the same power and brand that we used in the shop. Pond filters probably pump a little more so in comparson I'd say that what teflon is saying has some truth, but perhaps not all the time. The filter media would likely be a variable in this problem as well. Anthony Link to comment Share on other sites More sharing options...
wui39 Posted December 18, 2005 Share Posted December 18, 2005 Fair point Ant. Maybe its different sort of bacteria we are looking for. If flow rate was such a bad thing, I suppose FBF wouldn't work at all. But back to my first point, 3000Lph through a pond filter is not really anything big. That would be considered small for a pond filter in fact. 3000Lph through a cannister is big. Link to comment Share on other sites More sharing options...
Ash Posted December 19, 2005 Share Posted December 19, 2005 You have to remember a piddly little internal filter like the otto has maybe a litre of media with 1800lph going through it, whereas a cannister with 1800lph has 5-10l (roughly) pond filter is more like 20l+ with 3000lph going through it. The extra volume in the media chamber will slow the flow down across it's whole area. Picture 2000lph coming out of a 19mm hose, now picture it in a 50mm hose or a 100mm hose - it still has the same flow but the speed the water passes though the media is greatly reduced with volume. So yeah, in the extreme case Ant mentioned with lots of flow vs small media volume, it makes sense that the bacteria will have trouble - but anything larger will not have that issue, unless you go proportially nuts (say 10000lph through a 20l pond filter) Does that make sense? I don't know for certian, but I'm pretty sure I'm on the right track. Unless Ant was discussing a 1800lph external cannister, then I guess the whole thing shifts down a notch but still applies. HTH Ash Link to comment Share on other sites More sharing options...
steve24cro Posted December 19, 2005 Author Share Posted December 19, 2005 thanks for the ideas, i was thinking just as some of you were saying, to use a extra large pond filter (for the filter volume) around 30 litres and either a 2000 or 3000lph pump, which is really nothing for filters of such volumes. But i was thinking could you use filter media in their like find sponges and matrix to poilish water more?? Link to comment Share on other sites More sharing options...
Ant Posted December 20, 2005 Share Posted December 20, 2005 Yes was talking about an external cannister. I get your point and it does make sence. Anthony Link to comment Share on other sites More sharing options...
teflon Posted December 20, 2005 Share Posted December 20, 2005 There was a discussion on ace about the "bacteria debate" im not saying i know this to be factual because of research its just something i thought i would mention as a few people said it cheers Link to comment Share on other sites More sharing options...
Adam Posted December 20, 2005 Share Posted December 20, 2005 Teflon is correct. If you have to much water flow per volume of filter media you will blast the bacteria off the media. FBFs don't actually require a high flow rate for the amount of material in there. They rely on seperating the sand grains so that you have high surface area for the bacteria to grow on. More flow through the filter is not the answer to biological filtering. It is more media for bacteria to grow on. I make my own canisters out of 100mm or 150mm PVC pipe. I make them to suit the amount of media that I want them to hold. Have an inlet at the bottom and an outlet at the top. I put a screw cap on the top so that I can put the media in and get it out again to clean it. Adam Link to comment Share on other sites More sharing options...
wui39 Posted December 20, 2005 Share Posted December 20, 2005 Okay so we now agree that high flow through a small volume doesn't work, getting back to the original question about a pond filter. How many pond filters are small like a cannister? I only responded to Teflon's comment because it seemed to imply that it wouldn't work. Is 3000L through a pond filter too much? Most pond filters are the size of and carry the same volume of media as a sump filter. Sump filters seem to work. Could you send me a pic of your design Adam, I've always wanted to make a DIY cannister but didn't get around to it. What is the pump your using on that? Link to comment Share on other sites More sharing options...
Adam Posted December 20, 2005 Share Posted December 20, 2005 3000l/hr through a normal sized pond filter is not to fast. It will work very well. Are they a sealed unit that can be pressurised? I used a pump that delivered 10,000l/hr through a 150mm PVC tube approximately 1.6m tall with 20l of bioballs. It worked very well on some very heavily stocked tanks. I obviously used a sump to put the pump in. I've given most of mine away as I have started using sand filter housings to hold my media. But I think I've got one the dogs knocked over and broke. It'll show some of the internal piping that I do so I can have my fittings up high. I'll post when I can take them. Adam Link to comment Share on other sites More sharing options...
Adam Posted December 23, 2005 Share Posted December 23, 2005 I haven't taken any more photos but found these ones on my web photo host that I took a while ago. Hopefully self explanatory, if not ask. Adam 150mm Filter Link to comment Share on other sites More sharing options...
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