Spin Down Filter - Which micron rating?

[aquaventions]

I am going to purchase a spin down filter manufactured by RUSCO (add .com for their website), and I could use some advise about which mesh/micron rating I should select. Water from the tank will enter the spin down filter before reaching the two Eheim 2028's.

Centrifugal force will force larger particles to the bottom of the filter housing where they can be flushed periodicaly through a valve on the bottom of filter. The smaller particles trapped on the screen will also be flushed out when the valve is open.

The screen can be cleaned as often as necessary requiring no replacement.

While their screens go down to 15 microns the surface area is no where near that of a sediment cartridge so the manufacturer suggested no smaller than 30 microns (500 mesh).

Now, RUSCO is unfamiliar with aquariums so I'd appreciate some advise from those who are.

In case it helps I'm adding a UV lamp with a one micron 20" sediment cartridge preceeding it. The UV will follow the Eheim's.

 

[nolapete]

Aquaticeco.com has micron filters that range from 1000 to 1 micron. You could stage several ahead of it to get what you need.

 

[brianp]

My view is that the use of this filter type is both unnecessary and potentially quite problematic in terms of maintaining reasonable water flow to the canisters. The reason is that aquariums produce large amounts of complex viscous, mucinous debris which I think will clog a 30 um filter quite rapidly. There is continuous bacterial turnover and every time a bacterium dies, it spills its DNA into solution. DNA is a large, viscous polymer that will rapidly clog filters. The fish are continuously shedding mucous from their slime coat and the suspended fecal particles...oh boy! I would imagine that a polyester water polishing pad in the canister would be more than sufficient. Finally, I do not believe that yet another filter preceding the uv unit is necessary.

 

[cchhcc]

DNA is too small to be mechanically filtered out.......even if one chooses to accept your opinion. Also, the cleaner the water exposed to UV the more effective the UV. It is standard practice to position sterilization post filtration.

Most people get good results with 200 micron ratings. 100 will also work but will need to be cleaned more often.

 

[brianp]

DNA is too small to be mechanically filtered out.......even if one chooses to accept your opinion. Also, the cleaner the water exposed to UV the more effective the UV. It is standard practice to position sterilization post filtration.

Most people get good results with 200 micron ratings. 100 will also work but will need to be cleaned more often.

I can assure you that undegraded DNA is a big problem from the standpoint of clogging membranes and filters, particularly in the 30 um pore size range. We encounter this problem frequently in our product design. Now, it's quite true, that I have never filtered aquarium water with a 30 um filter, so I admit that I am speculating with regard to "DNA and mucous clogging". However, I'll bet that a 30 um filter would have to be cleaned or replaced almost daily. But yes, this is just my opinion. Also, many/most individuals attach their uv unit downstream of their canister filter and that should be sufficient pre-filtration.

 

[cchhcc]

I can assure you that undegraded DNA is a big problem from the standpoint of clogging membranes and filters, particularly in the 30 um pore size range. We encounter this problem frequently in our product design. Now, it's quite true, that I have never filtered aquarium water with a 30 um filter, so I admit that I am speculating with regard to "DNA and mucous clogging". However, I'll bet that a 30 um filter would have to be cleaned or replaced almost daily. But yes, this is just my opinion. Also, many/most individuals attach their uv unit downstream of their canister filter and that should be sufficient pre-filtration.

Oh, I totally agree that a 30 micron filter would clog almost daily (maybe more!). I'm just saying that DNA isn't the culprit......it's in the makeup of the biofilm, but not clogging on its own.

We're probably just saying the same thing with different words.