is tds of 37 ok

brettinteriors

New member
Tested my used 5 stage ro and got a reading of 37. Tap was 172. I don't know what the ro water I buy is. Obviously 0 is optimal but I don't really want to spend $60 on a di now. I have a few coral(thanks Gary), and will want more in the future. What is a reasonable tds reading or range for a reef tank.
 
You need a DI, without it you will never get to 0. I am not saying that you can not use RO only and have good results but for 60.00 why even risk it :)
 
What brand, did you buy new? My water is 250-280 going in and 7-8 before it goes to the DI. I think you have a problem or a bad TDS meter
 
What brand, did you buy new? My water is 250-280 going in and 7-8 before it goes to the DI. I think you have a problem or a bad TDS meter

I got a used watts premier wp5 for $30. Person had no idea when the filters were changed. I will have to change the filters and add a di.

I just ran 5 gallons through and it is down to about 15.
 
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I would defiantly replace the filters. Would you buy a used car, that the seller has no idea when the last oil change was, and not imediately change the oil? That might bring you down to the 7-8 that tucsonreef is at.
 
Yes replace the filters, but you might still stay at 15, there is a big swing between membranes some do better then others. Replaceing the filters takes out some of the sediment and also the clorine which will eat up you membrane. The lower you can get it going into your DI, the longer you can go between DI changes.

If your RO is only used once in a while and not daily, shut off the source and bleed off the RO for a few minutes before it goes to the DI when you turn it back on. This will get the bad water out of your unit and save your DI from the junk water.
 
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