RO membrane cleaning

[Karyn Rees]

Hi !

I was wondering if I have it right...to descale calcium buidup, can I use a powerhead to pump acidified RO water through the unit by the normal route for water feed...pumping it through the empty prefilters and through the membrane...just like when it's attached to the faucet ? Then collecting the water and recirculating it.

Is this correct ?

Thanks !

[decula]

Hey there.

I might be concerned about anything breaking loose and collecting on the membrane in the
above scenario. The folks I got my RO system from have a wash valve that just bypasses the
restriction to allow more flow over the membrane. I think the main thought here is the membrane
is the more costly item to replace and that a failure there is the most costly on the fish.
Maybe remove the membrane as well as the filters?

4 posts - welcome to SimplyDiscus!

-dec

[Karyn Rees]

Hey there.

I might be concerned about anything breaking loose and collecting on the membrane in the
above scenario. The folks I got my RO system from have a wash valve that just bypasses the
restriction to allow more flow over the membrane. I think the main thought here is the membrane
is the more costly item to replace and that a failure there is the most costly on the fish.
Maybe remove the membrane as well as the filters?

4 posts - welcome to SimplyDiscus!

-decThanks, decula. The old RO is down to producing a trickle. I already started on it...


I first took out the prefilters and tested flow...membrane still not working much. So I tried the powerhead...didn't produce enough pressure I guess - so I filled all the prefilter containers with warmed acidified RO and then attached it back to the faucet so that faucet water would drive the acid water into the membrane container. I let it sit for a few minutes and then let it run a bit, put back in the prefilters and ran it.

Flow is improved a bit but not much. It now almost gives a stream instead of drops of water coming out. Since I don't have a booster pump, I think the the other option is to let the membrane stand in acid water in upright position overnight.

Karyn

[TURQ64]

Thanks, decula. The old RO is down to producing a trickle. I already started on it...


I first took out the prefilters and tested flow...membrane still not working much. So I tried the powerhead...didn't produce enough pressure I guess - so I filled all the prefilter containers with warmed acidified RO and then attached it back to the faucet so that faucet water would drive the acid water into the membrane container. I let it sit for a few minutes and then let it run a bit, put back in the prefilters and ran it.

Flow is improved a bit but not much. It now almost gives a stream instead of drops of water coming out. Since I don't have a booster pump, I think the the other option is to let the membrane stand in acid water in upright position overnight.

Karyn
I think the OTHER option is a new membrane; it's part of the cost of doing business with R/O

[Karyn Rees]

Hi Turq

Yeah, I think so. Although others report good results from descaling, Dow tech literature says it probably won't help enough once it's far gone. So I'm putting in a new membrane now. Good thing I bought 3 last time.

I'm finally going to break down and get a booster pump too.

Thanks Turq,

Karyn

[Karyn Rees]

This install of a new membrane is looking way better than some of my previous installs/membranes. It's the same model of filmtec 100 gpd I've been using, but this time I did not change out prefilters > I've noted that no matter that on first start-up I've rinsed the carbon on high flow before connecting to the membrane, and also later rinsed out the housing a couple of times, that there is always a small amount of black residue in the carbon block housing or on the cartridge exterior. ( 5 stage with sediment, granulated, block )
I think that I will keep the old carbon block in place as I "break in" the new carbon granulated and block cartridges ...not going to change out all the prefilters at once this time. I would like to put another small micron sediment filter last in line for that reason, but I might require a booster pump then, not sure. Next time I'll change prefilters before changing membrane, as well.

Also I took extra care in lubing and manipulating the membrane into the housing.


This time I seem to be getting a good deal more product water, than ever.

[Karyn Rees]

It worked out to be producing approx 80 gdp, and that is with all old prefilters and lines and valves, tap pressure @65 lb.

Can I run a little hot water to mix with the cold ? Seems I could get 100 g. a day out of this, just with a bit higher temp.