Dkeller_nc
Well-Known Member
- Joined
- Mar 2, 2019
- Messages
- 893
- Reaction score
- 1,269
- What state or country do you live in
- North Carolina
Chicago - as you've found out (and why Buckeye is asking about your incoming hardness), scaling/fouling is an issue with RO membranes. That's the reason for your electronic controller's flush cycle - the theory is that whatever precipitates out on your membrane will be re-dissolved when the flush of incoming tapwater (without the concentration effect of the RO membranes) runs past the surface. In industrial systems, especially in areas with a high dissolved divalent cation and/or sulfate concentration in the water, injection of anti-fouling chemicals are used to keep precipitation of these compounds from prematurely clogging the membranes.
In your case, I'm guessing the really low temperature is hurting you; while the TDS of your incoming water is fairly low, the saturation point of most ionic compounds goes down significantly with temperature (calcium compounds are an exception). It's hard to know without an actual chemical analysis of your incoming water, but it may well be that you're near saturation of some of these compounds at 42 deg F.
If your system is inside your house, and your house is at a reasonable temperature (65 deg F or above), one way to increase the incoming temperature is to put a 50 ft coil of RO tubing between your incoming sediment filters and your RO/DI unit. The room heat will slightly heat the incoming water, though the degree of heating will depend on the temperature of your room and the flow rate through the tubing. A second way of altering the incoming temperature is to put that same 50 ft. coil of RO tubing into a tank of water, and add a heater to the tank. Heat conduction through water will give you far greater heat transfer than just the coil of plastic tubing in air; adding a circulation pump to the water tank will increase the heat transfer further.
Finally, the most effective and also the most $$ in equipment for heating the incoming water would be to put a direct heater actually into the incoming water line. Essentially what you're doing is putting in something like a tank-less water heater into the incoming water path.
Personally, I'd suggest implementing those changes in the order listed; a coil of RO tubing is dirt cheap; if that doesn't raise your temp above 60 deg F, then try the water tank ( a 10 gallon rubbermaid container from the home store would do). If you still can't get the temp above 60 deg F with the water tank, a couple of aquarium heaters and a circulation pump, then you can consider whether it's worth it to you to put an in-line heater into the system.
In your case, I'm guessing the really low temperature is hurting you; while the TDS of your incoming water is fairly low, the saturation point of most ionic compounds goes down significantly with temperature (calcium compounds are an exception). It's hard to know without an actual chemical analysis of your incoming water, but it may well be that you're near saturation of some of these compounds at 42 deg F.
If your system is inside your house, and your house is at a reasonable temperature (65 deg F or above), one way to increase the incoming temperature is to put a 50 ft coil of RO tubing between your incoming sediment filters and your RO/DI unit. The room heat will slightly heat the incoming water, though the degree of heating will depend on the temperature of your room and the flow rate through the tubing. A second way of altering the incoming temperature is to put that same 50 ft. coil of RO tubing into a tank of water, and add a heater to the tank. Heat conduction through water will give you far greater heat transfer than just the coil of plastic tubing in air; adding a circulation pump to the water tank will increase the heat transfer further.
Finally, the most effective and also the most $$ in equipment for heating the incoming water would be to put a direct heater actually into the incoming water line. Essentially what you're doing is putting in something like a tank-less water heater into the incoming water path.
Personally, I'd suggest implementing those changes in the order listed; a coil of RO tubing is dirt cheap; if that doesn't raise your temp above 60 deg F, then try the water tank ( a 10 gallon rubbermaid container from the home store would do). If you still can't get the temp above 60 deg F with the water tank, a couple of aquarium heaters and a circulation pump, then you can consider whether it's worth it to you to put an in-line heater into the system.
