Filtration - Microns

[Plum]

I have been reading quite a bit in regards to filtration, and asking many q's to JohnPTC (thank you), but thought I would ask this aloud so that perhaps others could learn from the question as well.

I have read that sand filters filter the water to 20-40 microns, but what does this translate into?

Does this mean more regular flushings? Higher wastes found in the tank? Plainly more maintanence?

What are the benefits of choosing a filter that filters the water to 2 microns - as an example?

Can it be quantified, or at least a clear answer as to - YES it is healthier for your fish, no debate?

Health of the fish is my main concern, but if this can be solved by just flushing more - I don't forsee this as a problem.

I suppose flushing water regularily would equate in having to heat up the water more often (ie higher cost on a 960G) but I think I am getting quite trivial with this point.

Thanks,

Plum

 

[Pharaoh]

Sand filter do do a better job of getting fine particulate. This would translate into very clear water. Only downside, the more efficiently you filter, the more you will have to flush the sand to get the debris out of it.

you shouldn't have to flush the whole tank, just the sand in the filter. I assume you are talking about a fluidized bed filter or an actual sand filter?

 

[Plum]

some examples of what I am looking at are;

Hayward Sand Filter
Hayward DE series
Aquadyne bead filters

 

[Jgray152]

What size aquarium is this filtration going to be used on and at what GPH flow rate you shooting for?

 

[Plum]

1 - 960
1- 720

I am unsure really what flow rate I should be aiming for. I would like to turn the water over 5x minimum / hour

 

[Knowdafish]

1 - 960
1- 720

I am unsure really what flow rate I should be aiming for. I would like to turn the water over 5x minimum / hour

5 x 960 = 4800

5 x 720 = 3600

Up to you how much turn over you want. 5-10 times an hour is good.
What kind of fish? Larger/messier fish = higher turn over.

 

[Toby_H]

I have read that sand filters filter the water to 20-40 microns, but what does this translate into?

40 micron is a little under .0016 or 1/625th of an inch… or one 1/25 of a millimeter… So it’s not microscopic but it’s really darn tiny.

Does this mean more regular flushings? Higher wastes found in the tank? Plainly more maintanence?

Set up is the key. If you have the sand filter in line after ample mechanical filtration has already taken place, then the sand filter will only have to deal with the finest of particles which is exactly what it is meant to do. The most practical way to do this that comes to mind is to use the sand filter inline with a pump returning ‘clean water’ from the sump to the tank. What I’ve read about sand filters says they function best after they have a little debris in them.

I would think the biggest challenge to using a filter designed for a swimming pool would be flushing the filter without making a mess. If they are designed so you can put a hose on them and flush them through that hose I think it would work marvelously as a compliment to mechanical filtration.

What are the benefits of choosing a filter that filters the water to 2 microns - as an example?

1/12500th of an inch… which I do believe is technically microscopic… I would guess that the particles under 40 micron, but over 2 micron, would be unnoticeable to the eye as well as the fish… So I would suggest 2 micron is unnecessary overkill...

Can it be quantified, or at least a clear answer as to - YES it is healthier for your fish, no debate?

I have no evidence to support this thought… But I would believe that fish have evolved in an environment with small particles in the water long enough for them to have the means of dealing with them without ill result…

 

[Plum]

5 x 960 = 4800

5 x 720 = 3600

Up to you how much turn over you want. 5-10 times an hour is good.
What kind of fish? Larger/messier fish = higher turn over.

I plan to use the 960 for my 15 pygocentrous (piranha) which yes are pretty messy. Turning over that water 10x though would be quite a challenge - I might have to put them into the 720G.

I plan to place Pristobrycons or Serrasalmus in one of the large tanks, which are not nearly as messy as the other piranha's.

 

[Plum]

Yes - the pool filters are set up for a hose to be used when back flushing. I have put 4" floor drains around the basement so that I can preform water changes quickly through a filter of this sort.

I did not realize that 40 microns was 1/25th of a millimeter. I certainly find this to be extremely small, and quite unsure if it could really be noticible to the naked eye.

interesting....

 

[Miguel]

Aren't sand filters dangerous if the power is cut?