I read an article discussing filtration and suspended particles...more specifically pertaining to the speed of which the water is moved through the mechanical filtration. I suspect(as my tank has an excess of filtration on the highest setting), that perhaps this is a concern. An interesting aspect I never quite considered. Thoughts? Opinions?


"Most mechanical filters do a great job of trapping some particulate matter, but unfortunately they don't get it all.They have a tendency to move the water too fast, thus breaking the particulate matter into smaller pieces. The very small pieces tend to become suspended. These suspended micro particles contain the dangerous heterotrophic bacteria that can potentially cause great harm to our fish. The bacteria should be kept away from our fish, but these suspended particles do the opposite. They are in the water column and are very harmful.

Filters that move water through the aquarium at higher speeds, cause this problem to become worse. Small waste particles are the enemy. Filters that move water too quickly and those that create a large amount of small bubbles, break these particles into even smaller pieces and will actually cause this bacteria to become an even greater problem. To encourage small waste particles to settle in the filter chamber, water movement must be the slow enough to cause the particles to settle.

Most aquarists worry about ammonia and nitrites. However, they are easily controlled and seldom a problem for anyone other than a beginner with poor husbandry practices. Dissolved organics and heterotrophic bacteria are the real concerns, yet they are almost impossible for an aquarist to detect. It is critically important to keep them at low levels. Water changes are the most effective way to do this."

I bring this up b/c I have 2 400 GPH Emperor filters in my 55 gallon on the 'highest' setting to facilitate moving the biowheels (as they have a tendency to slow or stop with lower water flow),and an air wand and stone, thus I have quite a bit of current and surface agitation (one might say an 'excess' of current and surface agitation). Yet despite frequent water changes and fine water readings I seem to notice suspended particles that cloud the tank when I look through it from the side...from the front the tank looks clear, however. I am going to lower the pressure settings to see if this might help alleviate the issue a bit.. I do not think bacterial bloom is an issue due to the water conditions and the fact that I only use the lights for maybe 2-3 hours in the evening tops, and the tank is not subject to very much natural lighting and remains rather dim during the day. There are no natural plants.

The thing is...I'm thinking the bubbles are lifting particles from the substrate and circulating them, yet the filter perhaps is either moving them through too fast and creating these smaller particles...or the bubbles are creating enough of a current that the particles are revolving around in the tank and not entering the intake tube. So, either too much intake pressure, or too many bubbles and not enough intake pressure...it's a riddle wrapped in an enigma.

An interesting statement & certainly something that we should be aware of. I think it's quite easy to get complacent if you have got a large filter. I think keeping it as clean as possible from waste trapped in the mechanical filtration is probably a very good idea.

The problem is, if you've got a very large aquarium with quite a lot of fish then you need to have the water circulating at a certain rate, if it doesn't circulate quick enough then you are going to run into water quality problems. I don't think we should start getting worried if we are keeping up with an acceptable maintenance regime.

OFL wrote:


Well, I'm not really worried per se, as the fish are fine and the water parameters are exactly as they should be, however it has remained a frustration for me to notice the cloudiness visible from the side view. I am more than anything irritated and actually very curious as to what this could be. When I stick my nose on the glass and look up etc. I notice minute particles floating around...which seemingly look like very, very tiny bubbles (or very small rocks that float like witches). I suspect this is the cause of the cloudiness when viewed from the side, as I assume a bacterial bloom, water quality issue, etc. would be noticeably cloudy from all angles. Anyways, I'm reluctant to use water clarifiers.

OFL wrote:


I fell into the trap of "large filter less cleaning" but a few months ago realised the error of my ways. I would leave the filter 3/4months at a time before cleaning, but noticed my nitrates where getting higher at a steady rate for no reason. I went back to monthly filter cleaning, even though they are very clean looking inside. nitrates dropped from 20-30, 20pph being after a water change and 30pph before, to a very steady 10pph for before and after W/C. it was surely down to crap and my large filter just became a nitrate producer cos i was over filtered and could get away with leaving the cleaning for so long. who likes cleaning anyway some of the filter companies produce these polishing pads that trap very fine matter, again I have not used them but may try them, I know Necromancer use them and a few others. also I have noticed some of the arowana owners use a lot of good quality filter floss to do the same job. i got to say though my tank is 6ft long and when I look through the side its clear like drinking water. if it wasn't i would try to work out why.

I am not sure that water speed has much to do with water clarity unless it is too little. Mechanical media has everything to do with it. I use Poly-fiber floss for mechanical media and find it is superior than many of the retail filters. I contribute the superiority to having greater surface area to trap particulates.

On my wet/dry (trickle filter), I run a 950gph pump, 1200gph overflow, on a 6' too gallon tank with a 30 gallon sump. I would rate nominal flow at about 800-850gph. I too detect cloudiness when viewed from the end panel and non from the front. I then clean out the filter system and replace the media at that time. It will then be clear viewing from all angles until ready for next maintenance.

I feel that much of this "cloudiness" can be traced back to food being used and quantity of it. There is a definite change in length between cleanings based on the food being used (flake vs pellet).

I think the problem may be less when using a sump, for the water slows down in the seperate chambers, eventhough the flowrate of the pump is quite high.
On my other tanks I get the clearest tanks with the use of an external canister in combinaton with a HOB.
And Marcus, i had the same idea about cleaning the canister more frequent, for too much dirt came out the baby when i cleaned it this weekend.

increasing the lateral volume of filter media always make the difference with the
clarity of water. more surface to pass through, more suspended particles were catch.

PAUL wrote:


The emperor filters I have cam with empty plastic media baskets and spaces so I took them out and replaced them with mesh bags filled with ceramic rings. That way I can get at least twice the amount of rings in each slot, if not more, and still maintain the same water flow.

Very interesting - thanks for posting.

I recently added a powerhead with a supplemental mechanical filter. It does a fantastic job of removing the finer particles and polishing the water.

Just something to think about - perhaps something like this could add some extra insurance with a high-flow filter? It was very inexpensive ($10 US) and fits on the intake of a powerhead.

www.fosterandsmithaquatics.com/product/p...play.cfm?pcatid=4638

i do have this kind of attachment but i prefer the empty suction cartridge
where all the crap and waste are being drawn and delivered to the filter
box.....or canister... this attachment contains a polishing pad or sponge
that restrict the flow of water when gunk's embedded in it...

PAUL wrote:


All Ive done since is added extra sponge in front of the other media in the filter...