Originally Posted by 1077
I completely agree that filtering through finer material will produce cleaner water, but in well stocked aquarium's,overfed aquarium's,aquarium's holding large waste producing fish such as the larger cichlid's,I want water movement to keep that which I'm trying to filter, suspended longer rather than falling to the substrate.
Much easier for me to clean filter material than vaccum the substrate,and less dead area's for crap to accumulate.
Perhap's not as critical in tank's with few fishes , or plant's, but these appear to me,, to be the exception rather than what is often the norm for new hobbyist's and a few who keep large messy fishes such as the afore mentioned cichlid's, that if you ever watch a number of them eat,,, nearly half of what they take in, passes back out across their gill's while chewing/grinding their food, and fall's to the bottom.
Biological oxygen demand by bacteria on the substrate is significant, and if I can keep this crud to minimum between water changes,, Well then I'm a happy camper.
This raises a few good points. Having a fine (small) gravel or sand prevents uneaten food from falling out of reach. I switched to [pool filter] sand quite some time ago and think I'll likely never use gravel again. Everything stays on top of the substrate where unlike gravel, it is easily removed if desired during the weekly water change. Then again, also having a good cleanup crew helps. I quite like my Pepper Corys and find it amusing how they dimple the sand of the entire tank. Also, in a well planted tank, mulm (of uneaten food, plant and fish waste) in the substrate is just organic fertilizer for the plants.
Getting back to filters, although I (often) have floating plants, my rooted plants are currently plastic. I have always had crystal clear water and do not have an over size filter and/or power heads. Admittedly, I don't over feed and although my fish eat well, they are not the very large, very messy fish some have.
Still, I don't fuss 'n fret over any mulm on the bottom as this seems very natural to me. Aside from, or in addition to, organically fertilizing any existing rooted plants, the mulm feeds the beneficial bacteria (more than just nitrosomona and nitrobacter) in the substrate bio-filter.
With respect to filters, as it relates to GPH, I think there is a point of diminishing returns. If/when you have crystal clear water at 2x, it would seem pointless, in spite of the popular notion, to boost to 4x to 10x.
In another example, I have Abbeys turtle (along with 1-2 dozen fathead minnows) in the basement in a kiddie pool with about 60g of water. Under his sun deck is a perforated container with a 65gph pump filled with bio-max. Surrounding this is a fair quantity of polyester fiber. IMG_0002-w.jpg
This represents 1x filtration and for 3 months now, so far, the water remains crystal clear. In a different light, every drop is filtered every hour, 24/7 and that seems to do the job very well.
Finally, I have heard of even large planted aquariums using nothing more than a sponge filter that in terms of GPH is very low, but life goes on and water is clear.
So this is how I conclude that 4x to 10x is typically overkill, a myth and generally doesn't make water any cleaner or purer... it just moves more water, faster.