RO efficiency?

[brewmaster15]

Just curious what you all get for conductivity from your RO water units, when you have a new membrane.

[RandalB]

Al and all,
The best bet for lowest conductivity is the 75 GPD Dow Filmtec's the 100's will have slightly higher readings.

I am getting 6 uS (3 PPM TDS) out of my RO unit with 178 ppm Feed water. I am running the Aquatec 8800 Booster pump so my feed water is @ 100PSI+

Also be advised, the membrane is not always the culprit for higher out of the RO unit readings. As I've stated before the following factors effect the TDS and output volume of RO units:

1) Temperature: RO membranes are generally rated at 77F Below this, higher TDS and lower output (membrane efficiency is reduced)
2) Feed Water Pressure: RO membranes are rated at 50 or 60 PSI. Below this, higher TDS and lower output (membrane efficiency is reduced)
3) pH: Membranes are rated at 8.0. Above this, higher TDS and lower output (membrane efficiency is reduced)
4) TDS of Feed water: RO membranes are rated at 200 PPM TDS. Above this, higher TDS and lower output (membrane efficiency is reduced)

Number 1 and 2 have the greatest effect on your RO water and it's production. If you have cold, lower pressure feed water, you'll have high TDS readings, lots of waste and low production. Increasing pressure will overcome many of the other factors.


Interesting thread Al, do you need a membrane? ;)
RandalB

[brewmaster15]

Actually Randal,
I'm just trying to make a point that all R/o water is not the same :) because of all the factors you listed. :) and possibly others(maintenence on prefilters etc).

I Thinkmany often equate RO water with DI and they are not the same by a long shot.

I think depending on many of these factors this poll will show a broad range of conductivities that are infact being used by various people here. latter I hope to see if there is any "trends" in discus breeding successes. :)

Thanks for the offer of the membrane. :)

-al

[susankay1]

I dont understand how you find out what your conductivity of your water is. Could someone explain that please? Thanks ???

[daninthesand]

susankay1

You measure it with a conductivity or tds meter....

RandalB sells 'em at a great price.

Al. I get ~ 2 ms with my 100gpd, unit. Even in the winter with cold (~65 degree) water. No booster. Feed water around 220 ms. I'm pretty sure the membrane is from AMI (applied membranes)

Daniel

[korbi_doc]

:bounce2: :bounce2: hi guys, I get usually around 50ppms with my 100gpd membrane, lowest about 38ppm. Do use a booster, very necessary!! I reconstitute to over 300-350ppms for growth. The feed water is >900ppms thru a softener, which is easier on the membrane life. However, I am soon going to investigate the raw well water for nasties, (before the softener)cuz if I could use it, would make more water. The softener water (salt) was not good for my fish, caused lotsa problems early on. Anyone have a good (better) lab to use? Dottie ;D

[Smokey]

I agree with you Al.
Not all R/O's can porduce the same water numbers, when the intake waters are so diverse [ different areas, etc.].

EX - my raw tap town water is;
Ph = 8.4
GH = 450ppm
KH = 450ppm.

R/O unit a 2.5 by 14 inch Dow Corning unit. Rated for 150 gpd.
Feed water parameters are:
Temp = 85 degrees F.
Pressure = 100 psi.

R/O water produced numbers:
pH = 7.8
GH = ~175 ppm
KH = ~ 175 ppm.

The R/O is one year old now and the output numbers are still consistant.

On a final note - I understand R/O units are very popular; AND Some are better than others - efficientcy, life span, relaibilty. { correct? Randal].

Smokey
P.S. I still post condition the r/o water before it is introduced into the discus tanks. Black water is good!! lol. MPO....

[RandalB]

Smokey,
Pretty much accurate about the RO units except it's not the unit's themselves that are better or worse, it's the membrane elements in them. The RO unit might have a few nicer things than others, (IE JG fittings or clear cans or steel brackets,etc) But they are all essentially the same.

As far as your particular system goes Smokey, that's a 175GPD membrane more than likely (Dow doesn't make a 150GPD) at it is rated at 225 PSI which is why your product water isn't as nice as it could be.

HTH,
RandalB

[Smokey]

Correct Randal; I refered to the element as a r/o. .The add ons are just that add ons. Which make up a total unit. Thanks for the clairification.

And yes, it is a 175 gpd; us gallons... being in Canada - it is only 145 Imperial gallons.lol...

Pressure is very important, as I have been discovering. The guages show an incoming flow pressure of 100psi . This will acount for the output water numbers. correct[?].

Hmmmm - I do have a pressure pump. Trouble is it uses a lot of electricty.
It is mounted to a 1 horse power motor.

Randal - is there a graph which would give the different levels of efficienticy in relation to the input water pressure.??.
What is your personal expierence/suggestion.