coralife ro which water to use

I just got a coralife ro system.which water should I use tap or my well. I have great well water no smell tastes good. Brought it to my LFS they tested what they could the pH was a little low and the parts per million Were high. I just want to know what would be best for fish and filter?

 

If you have a softener on one or the other that would be the preferred source. Pressure also is a big deciding factor, the higher the pressure then happier a RO membrane is. The absoute minimum is around 40 psi and many domestic well pressure switches are factory set around 35 psi so that would make a RO inefficient compared to say 60 psi.
You mentioned the well water "parts per million" were high which probably means you have high TDS or Total Dissolved Solids and hard water which is harder on a RO membrane than low TDS (the national average is around 250 with areas of the southwest in the 600-1200 range and some cities like in the Pacific Northwest or Atlanta GA in the 50-75 range) and natually soft or softened water.

I would suspect you will be better off using your municipal tap water but a handheld TDS meter, a calcium carbonate hardness test kit and a pressure gauge will tell you what you need to know for sure.

 

Grab a tds meter and check both sources for dissolved solids. The one with lower dissolved solids would be better. It will help the filters last longer by reducing the amount of solids it is pulling out of the water. The tds meter can also be used to check your output and signal when it's time to change filters. I have an inline tds on my ro. It shows the tds going in at around 44 and the final product at zero.

 

Thats not quite accurate. TDS does not hold a candle to hardness. You cam have 500 TDS soft water and 200 TDS hard water and the soft water will win out every time. TDS does play a part but its really minor compared to hardness. It all depends on what the TDS is made up of.

TDS is not an indicator on when to change anything other than the RO membrane and the DI resin, sediment and carbon block filters have very little to absolutely nothing to do with TDS. They remove suspended solids, big floating particles, and chlorine. TDS o dissolved solids are in the 0.0001 micron range, a sediment filter is in the 0.2 to 10.0 and higher range so TDS passes right through.
The TDS meter does tell you when your RO membrane is bad or your resin is exhausted though but an inline meter is not the preferred tool unles you have a couple of dual inline TDS meters so you can test at least 3 points, tap water TDS, RO only TDS and final or RO/DI TDS. You need all three to troubleshoot a RO/DI system, two if it is RO only, tap and final. I would always opt for a good $20-$25 handheld TDS meter though as they are much more accurate, more versatile and can be used portable. Inlines are not truly temperature compensated so can be significantly off unless your air temperature and water temperature are exactly the same, which rarely happens. The inline probe is looking at air temperature not water temperature. A handheld like the HM Digital TDS-3, TDS-4TM or AP-1 series has a temperature probe in the water and also has a built in digital thermometer so serves dual purpose for the same money or less.

 

You guys are so good on here. I think your right the tap water would be best for the filter and fish.

 

I would drink the well water and use the tap for the RO or RO/DI. I miss having domestic well water, the minerals made it taste almost sweet!

 

My well water is so good. Most wells turn your walls orange and smell like sulfer.This stuff tastes like spring water but without testing it i am afraid to drink it. It is what my fish are using right now but I got the ro system because i know thats bad to do. I had one of those water people come test my tap water for a $25 chilli"s gift card. They said the same thing that i should use the well water instead of the tap. They tested for alot of stuff too. She said it must be a deep coquina rock well.