Whole house pre filter

[Trevor W]

Now I may be crazy in thinking that this is something worth trying, but before I do I would like other peoples thoughts on it.

My idea is to install a whole house pre filter like the photo below (a larger version of the pre filter on your RODI unit) on the drain line coming from the main drain of an overflow ( in my case the herbie method) and going to the sump. In effect taking the place of filter socks. I am guessing that the pre filters they sell would likely last alot longer than how often filter socks need to be cleaned or changed/rotated. Yes I can also see it becoming a nitrate factory if neglected but with filter replacements usually being quite cheap it wouldn't be IMO too much to change it once a month or every other month depending on how long it would last. What do you guys think? I tried searching to see if this has been done but I couldn't seem to yield any results. Would love to hear your thoughts.

[mark]

considering how dirty my socks get could see that working on my display for about a day before it would plug up and I'd be relying on my Herbie emergency.

[Trevor W]

Originally Posted by mark

considering how dirty my socks get could see that working on my display for about a day before it would plug up and I'd be relying on my Herbie emergency.

After running filter socks on my tank aswell I do know that they can get quite filthy fairly fast,...I guess I am more curious to find out if they would last longer being that they are by design built to take on more particulates than a simple filter sock or perhaps thats just my flawed perception of it.

[nrosdal]

if you were to try this you would want it on output side of pump as it needs to be pushed through the filter and the gravity fed thing would make your tank overflow everywhere when it starts to require some force to get water through (if not even right from the start). It will probably give you a month of use with decent flow through it as i ran a standard ro sized one as a pre filter to my carbon in years past and it would take 3-4 weeks to stop flowing through well on a maxijet.

[Ryanerickson]

In my opinion it's not a good idea it will slow down to the point the drain can't keep up and possible one day flood if the emergency can't keep up I have done something like that before but it was on the return and had a 1.5" in and out worst case with that setup would be return slowing down. By the way I found putting the prefilter on the the return just a waste of time.

[Trevor W]

Originally Posted by nrosdal

if you were to try this you would want it on output side of pump as it needs to be pushed through the filter and the gravity fed thing would make your tank overflow everywhere when it starts to require some force to get water through (if not even right from the start). It will probably give you a month of use with decent flow through it as i ran a standard ro sized one as a pre filter to my carbon in years past and it would take 3-4 weeks to stop flowing through well on a maxijet.

Yeah I was kinda curious about the pressure involved to filter the water through a typical cartridge. I know you can get different styles of cartridge that are more like a pleated pool filter style but I assume it would be no different and the flow from the drain would not be sufficient enough to properly flow.

Originally Posted by Ryanerickson

In my opinion it's not a good idea it will slow down to the point the drain can't keep up and possible one day flood if the emergency can't keep up I have done something like that before but it was on the return and had a 1.5" in and out worst case with that setup would be return slowing down. By the way I found putting the prefilter on the the return just a waste of time.

I never thought of using the pressure from the return pump, but yea I can see how putting the prefilter on the return might seem to be a waste of time.


Thanks for all the input

[sphelps]

Those house filters typically run on 40+ psi and even then the flow rate required through them is fairly small. Now compare that to your typical herbie, if you got three feet of water on top if it, it's only around 1.5 psi or so and the required flow rate would be pretty high as well. Even on a return pump the pressure won't be much higher. The other issue is your tap water is actually really clean, for example if you ran filter socks under your faucets they'd probably never clog up.

[Trevor W]

Originally Posted by sphelps

Those house filters typically run on 40+ psi and even then the flow rate required through them is fairly small. Now compare that to your typical herbie, if you got three feet of water on top if it, it's only around 1.5 psi or so and the required flow rate would be pretty high as well. Even on a return pump the pressure won't be much higher. The other issue is your tap water is actually really clean, for example if you ran filter socks under your faucets they'd probably never clog up.

Very true...thanks for the input. When I first thought of this I will admit that I never realized that these filters required the amount of pressure that they do. I initially thought that it would act similar to a pre filter sponge or something equivalent that water would easily flow through. I guess these would all be good reasons why I couldn't find any info out there on people using them in place of filter socks or floss.