R/O units

[Bartman]

Originally Posted by mr_alberta

I think Dan is implying that there is more room for error (i.e. accidentally running only hot water to the unit) when hooking it up to the hot water line and killing your membrane.

I am just waiting to receive my Aquasafe unit and I ordered a faucet adapter. I understand that RO membrane capacity is rated at somewhere around 75F, not cold water temps. I was planning on running with the same temp water I use for my FW tanks (around 74F). Is this safe?

[vanreefer]

Originally Posted by Bartman

Just curious, why would warm tap water kill your membrane but warmed water through a coil would not?

the warm water from the tap (hot water heater) could (usually does) contain heavy metals that leach out of the tank. I use warm water from the tap makes a huge difference in RODI water production

[Paverdude]

My r/o unit has a small pump w/ pressure switch bumps it up to 125psi.

[Dad]

The manufacturer doesn't tell you what temperture you should have but does say you need at least 45psi. I did put some of the hose in my sump to help warm up the water and it did help, last night in 8hrs I got 12gals which equals out to 36gpd, thats up from 17hrs and 11gals. Tomorrow I will post temperature & TDS going into R/O and temperture & TDS coming out of unit.

[b_james]

My instructions do mention that lower water temp will slow RO productions and increase waste water as well. I think DanG has something there. By increasing the legnth of the 1/4" inlet line and coiling it up and submerging it into your sump or a bucket of heater water would be a good way to temper your water supply. It shouldnt take much energy to temper water in 1/4" tubing. I think Im going try making myself a simple flow through heat exchanger.

[StirCrazy]

I get about 200 gpd from my unit this time of year, in the summer about 280 gpd.

One thing to note that a 100 gpd unit might realy be a 65 gpd at 60 PSI, most membrains ate dual rated ie. 65gpd@60 psi/100gpd@90 psi. My membrains are 90GPD@60PSI/160GPD@90PSI.

so if you are running them at 55 PSI you are going to be even lower than the 65 GPD and then cold water is a huge difference as they are usaly rated at warmer water also.

Steve

[Beverly]

b_james,

Could you please do me a favour and test ammonia levels of the water that comes directly out of your RO/DI unit for me? I'm getting .5 ppm ammonia out of my unit. Here's my thread on this issue....

http://www.canreef.com/vbulletin/sho...136#post186136

TIA

[crusty1]

As you raise the water temperature the membrane opens up and allows more salt passage, leaving the DI resin to do more work. I just found a data sheet that recommends Filmtec FT30 membranes to run at a max of 45 deg C. I think that is a pretty standard max temp on all TFC membranes.

[Dad]

the test results are; the water going into the r/o unit is 46f and the TDS is 220 and the water coming out is 65f and TDS of 004. Running the coil of line into my sump warms the water 20 degree and will check the gals tomorrow moring.