I had no idea before I got into this hobby about 1.5 months ago. I bought my ro/di from BRS and set it up to make water the other day hoping I would get at least 50psi. Welp, it hit the magic # that BRS recommends, 50psi. My TDS was 70ppm. According to my water company, my water is treated with chlorine, chloride, and phosphates.
Who actually has 40+ psi of water pressure from their house?
- Thread starter b4tn
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As many know, RO membrane performance is specified at a particular water pressure (psi) and a particular water temperature. But few know that the performance is also specified at a particular feedwater TDS (ppm). Filmtec 75 gpd membranes for instance are spec'ed for use with feedwater at 250 ppm TDS. If you have higher feedwater TDS than the membrane spec's, you can compensate by adding 1 psi pressure for every 100 ppm TDS over the membrane spec. Practically speaking, let's say you have 400 ppm over the membrane spec... no one is going to get a booster pump to add just 4 psi - you'd use the pump's full capability and crank the pressure up higher than that.
Russ
Russ
Phil D.
Valuable Member
I get 72psi out of my faucet
Dkeller_nc
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This is worth investigating. The first step would be to get a 3-point TDS meter so that you can monitor the inlet TDS, the RO membrane output TDS and the RODI output. Either that, or connect your existing 2-point TDS meter to the inlet water and the RO membrane output. You should see about a 90% reduction, even at 45 psig inlet pressure. If so, then you're probably correct and you've a high CO2 inlet concentration, which can be mitigated with an storage reservoir with an air pump/purge after the RO membrane. You'd use a pump to push this water through your DI cartridge(s), but it doesn't really have to be a bonafide RODI system booster pump because it's not working against a really high back pressure.
If you're not getting 90% rejection, it's time to think about examining the seals around the RO membrane, or replacing the RO membrane if it's older than 6 months. Especially if your inlet water is municipal water treated with chloramine and you haven't been diligent in replacing the carbon cartridges in your unit.
I think you mean a float VALVE, rather than a float SWITCH.
A float valve is a mechanical device akin to what's in your toilet tank.
A float switch is an electrical device that opens (turns off) and closes (turns on) an electrical circuit.
Russ
Appreciate all this I do. It’s been a while since I tested my inlet tds. However last I checked I was getting over 90% rejection before and after I changed the membrane. I have a 7 stage I would say.
-5micron standard sediment change every 30days
(Sucker is chalk full of orange/iron)
-1 micron rosave filter change every 90
-1 BRS universal carbon block change every 6months
-1 membrane change every 18months
-1 cation stage
-1 anion stage
-1 BRS pro mixed bed
I also have it T off after membrane to go to drinking water. Extra carbon filter thing on way to drinking water tank. In addition, my setup is in the basement but my water tanks are on the 1st floor. So I need the actual pressure from the house to get to tanks.
I wonder if I gassed off how long my resin would last. Would buying a 50gallon brute, a few pumps and an airstone running 24/7 cost just as much? Would I get my ROI back in a year?
Any problems in setup or change schedule?
If you have lots of iron in your water, it is also affecting your hot water heater and every plumbing fixture in your house. If you ever want to talk about a whole-house solution, please let us know.
There are three common problems with well water, and they are often present together: iron, manganese, and hydrogen sulfide. Excessive hardness is also commonly an issue.
Russ
There are three common problems with well water, and they are often present together: iron, manganese, and hydrogen sulfide. Excessive hardness is also commonly an issue.
Russ
I lived in MESA....yeah basically you could skip the 2part almost lol
Where I live now I get river water and it runs through a heavily urbanized area; TDS is 600 , ph = 9ish and my psi is about 35 so BRS makes a small fortune selling me RO supplies lol
muzikalmatt
Valuable Member
I have 80+ psi with ~40 TDS on City water.
When you have a residential well, your well pump is controlled by a pressure switch. Common pressure switches are 30/50 or 40/60, meaning:
Pressure switch | Turns pump on @ | Turns pump off @ |
| 30/50 | 30 psi | 50 psi |
| 40/60 | 40 psi | 60 psi |
So let's say you have a 30/50 switch - you actually have a range of pressures - sometimes as low as 30, and sometimes as high as 50 psi.
Admann
Active Member
I have about 35 psi city water, 400+/- TDS. I run 0.5 micron sediment and carbons before the RO. Those only remove about 10 TDS. My RO reduces the 390+/- to an average of 7. The 2 stage DI brings it to 0.
I guess I am wondering what is in my city water that 0.5 micron sediment and carbons can only reduce by 10 TDS and my RO will remove over 380?
Time for a water test I suppose to really know. The sediment filter looks like a rusty pipe prior to changing it.
I don't really use an inordinate amount of filters.
I guess I am wondering what is in my city water that 0.5 micron sediment and carbons can only reduce by 10 TDS and my RO will remove over 380?
Time for a water test I suppose to really know. The sediment filter looks like a rusty pipe prior to changing it.
I don't really use an inordinate amount of filters.
Sediment filters and carbon blocks are not intended to remove TDS. Sediment filters remove UNdissovled solids, and we use carbon blocks to remove a dissolved gas - chlorine.
Admann
Active Member
Thanks, I just thought I would raise the question of what others with similar water parameters through their units found those contaminants to be. I think I will do a Triton or ATI to see what is in there. I hate not knowing what it is. Lots of iron is apparent, surprisingly no sulfide smell for Louisiana.
Iron does not play well with RO membranes... nor does it play well with your water heater, dishwasher, and other plumbing fixtures. We favor whole house solutions where iron is an issue.
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By the time my well water gets through an iron curtain and a softener its at 40 psi with 660 tds,
45 tds out of the ro, 0.3 ppm out of 3 stage di with no booster
Back when I had city water it was 68 psi and 100 tds from the tap
45 tds out of the ro, 0.3 ppm out of 3 stage di with no booster
Back when I had city water it was 68 psi and 100 tds from the tap
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