ro water filter

[inda_bebe]

so i bought an RO filter system. my city water is alright for making beer, but i wanted to make it better. so i bought this kit

http://www.amazon.com/Hydro-Logic-31035-100-GPD-Stealth-RO100-Reverse/dp/B002JLACGK/ref=sr_1_9?ie=UTF8&qid=1452016171&sr=8-9&keywords=ro+water+filter+system

So i collect to RO water and the waste water in a separate container. when i brew IPAs i usually use carbon filtered city water and 20% RO. How bad is the wasted water if i was going to use it for brewing? should be better than regular city water, right? its basically water thats been filtered from the RO and seperated.

 

[Yooper]

so i bought an RO filter system. my city water is alright for making beer, but i wanted to make it better. so i bought this kit

http://www.amazon.com/Hydro-Logic-31035-100-GPD-Stealth-RO100-Reverse/dp/B002JLACGK/ref=sr_1_9?ie=UTF8&qid=1452016171&sr=8-9&keywords=ro+water+filter+system

So i collect to RO water and the waste water in a separate container. when i brew IPAs i usually use carbon filtered city water and 20% RO. How bad is the wasted water if i was going to use it for brewing? should be better than regular city water, right? its basically water thats been filtered from the RO and seperated.

The waste water? It's where all of the "things" that are removed from the RO water go, so it would be unsuitable for brewing. It could be used for watering plants, or for washing clothes if you didn't mind using hard water for the washing machine (that's what I do).

 

[ajdelange]

The RO filter (black one on the top) can be thought of as a closed channel with 2 ends. Tap water is admitted into one end and through a large aperture and allowed to escape from the other end through a small aperture. One can adjust the pressure and flow rate through this setup by making the output aperture smaller or larger. One wall of the channel, along its entire length, is a membrane through which water molecules can flow but whose interstices are too small to pass molecules or ions of other substances. The RO water ('permeate') is taken from the other side of this membrane and the 'concentrate' from the outlet of the feed side of the channel.

A typical consumer unit is set (output aperture adjusted) up such that 20% or less of the feed water is recovered as permeate. This means that for each 5 litres of water passed through the unit only 1 litre of permeate is produced while 4 go down the drain. Suppose the feed contains 100 mg/L of some ion and suppose the rejection of this ion is 100% (unrealistically high). Then all the 500 mg of this ion in 5 L of processed water would wind up in the 4 L of concentrate so that the output concentration would be 125 mg/L. In general the concentrate concentration increase is 100/(1 - r/100) percent where r is the recovery of the unit in %. Commercial units may be operated at recoveries of 50% or more so that the brine may be twice or more than twice concentrated wrt to the original concentrations of any dissolved ions in the feedwater. But residential units are, as noted, usually designed for recovery of 20% or less and thus the 'brine' is likely to be concentrated by 25% or less. Depending on the nature of the contaminant and its concentration the brine may be usable in several brewing applications.

 

[Buckeye_Hydro]

so i bought an RO filter system. my city water is alright for making beer, but i wanted to make it better. so i bought this kit

One quick and easy change you may consider making is relocating the pressure gauge on that unit. Ideally, if you have only one gauge, it should read AFTER the prefilters (prefilter = any filter that processes the feedwater prior to the membrane). In this way, the gauge reads the same pressure the membrane gets. It's the RO membrane that is sensitive to water pressure.

With the single gauge after the prefilters, note what the water pressure is when your prefilters are new/clean. When you see the gauge pressure reading lower than the initial pressure, that's an indication one or both of the prefilters is clogging.

Russ

 

[ajdelange]

I'd take it one step further than that. I'd install a second gauge so that I could read the pressure drop across the pre-filters. Input pressures vary so that only being able to read the output pressure really doesn't tell you much.

 

[Buckeye_Hydro]

Better yet!