Filter questions

[GaryD]

Hi mopa,

Let me begin by reminding ourselves that a micron is 1000th of millimetre......or one 25,400th of an inch.....so a 200 micro particle is 1/5th of a mm......a pretty small thing only just visible to the human eye.

I guess my view on this is that 100 microns (a tenth of amm) is probably overkill from a sieve filter perspective for two reasons:

I'm of the understanding that wedge wire of less than 150 microns will not work in gravity feed mode......and will require a pump to force water through the mesh. This means that you would need to have a pump in your fish tank which is generally not the best place for it.

Wanting to go to the smallest wedge wire aperture possible ignores that a sieve filter is a great mechanical filter for the fact that it grabs the big particulate matter (fish faeces and uneaten food) and gets it out of the water column. Sieve filters are desirable for that fact alone.

Most of the remaining suspended particulate matter that gets through the mesh is going to be easily captured by a mat filter, a brush filter, a bag filter, a packed media filter......or a media grow bed.

The goal in filtration (from my perspective) is to remove as much of the particulate matter as cost-effectively possible without being a slave to the system. I'd probably opt for 200 - 300 micron. As Paul has indicated, even at this rate, you'll still need to clear the screen on a daily basis.

The presence of high concentrations of minerals would probably just limit the sieve filter even further.

Gary

[mopa]

yep 100 micron is tiny!! my plan is to to have 2 sieves daisychained , so gravity 300 micron to pumped 150 micron,i might go for.. the hard water element bothers me though.. lemon juice daily lol. as i intend to clean the sieve daily , i will clean 2 instead! better rinsing sieves than letting the muck get through the system and cleaning the rest of the filtration system a lot more often. will still get bio build up i guess on brushes but solids will be pretty much taken care of i reckon

[GaryD]

Hi mopa,

What about if you substituted a bag filter for the second sieve filter? Bag filters can be bought that will remove really tiny particles. I think I recall Paul (Earthan Group) saying that you can obtain them down to 5 micron but around 40 micron would be more than adequate I would think. This is equal to the smallest particle that you can extract with a rotating drum filter......if I recall correctly.

The oxygen-rich environment in a trickling or moving bed bio-filter would cope with anything that size and smaller.

Gary

[mopa]

yep bag filters sound great, but i am trying to get away from having to buy replacement filtration bits, so i would prefer not to. i understand you rinse them , but they need replacing eventually?

[greenfish]

I cant find any body talking about bead filters. Im considering placing one in between my gravity fed sieve and my moving K1.

[mopa]

personally i wouldnt go for them, as i have never heard of any koi users finding them spotless inside after their sieves. seen a few fotos of filthy ones, and it put me off them. they still need cleaning and are difficult to open.. and very expensive . and they need high pressure expensive pumps. think smallest one needs min 6000 l/hr personally i would go diy static k1 or eazypod
I would be interested in other peoples thoughts on beadfilters too..
regards

[GaryD]

Hi,

Bead filters are effective enough when it comes to solids removal but they do mess with water flow as they gunk up. I considered them but the cost and the pump issues sent me off in other directions.

I love the way that they clean.....particularly the bubble bead type.

Gary

[greenfish]

Thanks guys, I posted a link on my profile page to a video of my system. Its not perfect, and there is some unnecessary plumbing. Piss poor planning equals piss poor performance. Im still learning, mostly the hard and expensive way. Even with my return line split (one to Eazy Pod, one to fluidized K1 with sponge pre-filter), I still have to flush my easy pod every other day and clean sponge everyday. I feed 265grams twice a day.

The cleaning procedure is what attracted me to the bead filter. Im glad I got it cheap, cause now I'm leaning toward building a 50gal drum with static K1. Im trying to widen my cleaning intervals. And I need to get rid of that sponge pre-filter!

[GaryD]

Hi Greenfish,

Why don't you start your own thread and post your videos there? Having looked at the one in your profile, I think that they'd be of use to other members.

Im still learning, mostly the hard and expensive way. Even with my return line split (one to Eazy Pod, one to fluidized K1 with sponge pre-filter), I still have to flush my easy pod every other day and clean sponge everyday. I feed 265grams twice a day.

I've used the Nexus 300 and I own an Eazy Pod and, while they are both useful filters, we have to remember that they are essentially pond filters and not designed to take large slugs of biologically active waste......unless you want to become their constant companion.....as you're discovering.

I'm of the view that they will function best if another solids capture/removal device precedes them. This could be a sedimentation tank.....or any of the variations on that theme (like a swirl tank or a clarifer).....or a sieve filter.

In order of preference (for a system the size of yours), I'd opt for a sieve filter followed by a swirl tank....because the sieve filter removes the solids continuously and the swirl tank only requires the dump valve to be operated daily. This has the effect of extending the cleaning intervals......and will lead to the Nexus filter becoming more efficient. They seem to be less effective if they are cleaned too often or too thoroughly.

The cleaning procedure is what attracted me to the bead filter. Im glad I got it cheap, cause now I'm leaning toward building a 50gal drum with static K1. Im trying to widen my cleaning intervals. And I need to get rid of that sponge pre-filter!

What type/brand of bead filter do you use? Once again, any bead filter will work more effectively if you capture the bulk of the solids before they get to the bead filter.

Gary