picked up a spectrapure 90 gpd

So I got a spectrapure rodi this weekend. It's used but in nice shape. Only paid 50$. I was wondering how much water is usual to come out of the waste line while it's filtering. I have the book and need to do the test for the flow restrictor but it seems like I have a lot of waste water. thanks in advance.

 

Could be about 3x or 4x production. Look it up online.

 

ok, well that looks about right then. ill do the test with the flow restrictor like is explained in the manual to verify. Thanks

 

On average it will be 4:1 waste to good. IF and only IF you are using softened water and your tap water TDS is lower than normal you can reduce that 4:1 down to 3:1 or in rarer cases 2:1 if it is very soft and very low TDS. The waste ratio is what keeps the RO membrane well flushed so it performs as it should and lasts as it should. When you don't have optimum conditions and you reduce the amount of waste or ignore it and it is not what it should be the solids begin building up on the membrane and no amount of flushing in the world will correct it so it ruptures and fails.

Make sure you have a good handheld TDS meter so you can check and keep watch on the membrane and DI conditions and calculate your rejection rate.

 

What if you use one of them
Pelican Carbon Series Whole house water filter
for your water vs a water softener? It's supposed to stop Scale build up and uses carbon and other media to remove impurities for the whole house. Then use the RO unit will the waste ratio be further reduced?

 

No, carbon filters are intended for taste and odor removal, chlorine removal and maybe a little suspended solids removal. They do very little to absolutely nothing for ion exchange or softening the water which is what the RO membrane is looking for. A RO or RO/DI already has a carbon block filter as part of the filter and it is probably much better than the whole house filters granular carbon. The Pelican filter claims to remove chlorine and chloramines but says nothing about softening the water. If all you want to do is remove chlorine for the whole house, a $50, 20" carbon block will do the same thing and for a heck peck of a lot less money. If you are wanting a softener places like Sears, Lowes and Home Depot are very competitive if you don't mind adding salt or potassium every couple months at a cost of about $4 a bag or you can lease a system from Rayne or Culligan and let them take care of the maintanance but it costs you more.

Pelican is also on the list of questionable vendors using non scientific claims as found here:
http://www.chem1.com/CQ/gallery.html

 

OK I understand. I originally had purchased an RO Buddie and decided to return it, in part on your previous threads about RODI filters. I have a tap water filter for DI but with the cost of the media and the little amount that it actually will produce, I decided the Spectrapure would be a better bet. Just happened to find one on craigslist for an amazing price.

A TDS meter is on the list. I have yet to test my water at the house but being city, i'm sure its far from perfect.