Ro/di Water

[LICREEK]

How high can the TDS number get before i need to replace the filters?? Right now im getting 7 ppm TDS...Tanks, Lee

 

[DrBDC]

Change your di resin. You really should when you see 1-2 tds increase over new di resin levels.

 

[Thefilterguys]

If it was 0 to start with your already seeing problems in your tank. Once DI resin is exhausted it starts throwing back what it has stripped. Your corals start to show the effects fairly quickly.

Jim

 

[Unresistible Blue]

Re: Ro/di Water

<a href=showthread.php?s=&postid=7956433#post7956433 target=_blank>Originally posted</a> by LICREEK
How high can the TDS number get before i need to replace the filters?? Right now im getting 7 ppm TDS...Tanks, Lee

Before you replace all your filters, some probably needlessly, give us the tds readings in three locations:

tap water tds?
post RO (pre-DI) tds?
post DI tds?

how long have your prefilters been in place?

what is the chlorine capacity (in gallons) of your carbon block?

Are you seeing a pressure drop (an indication one or more of your prefilters are partially clogged).

 

[LICREEK]

Here are my numbers pre filter tds/153 and psi is 89lbs. psi after pre-filters is 87lbs. post r/o tds is 16 and psi is 80lbs. my post d/i is now at 8...looks like i need resin??...Thanks..Lee

 

[Unresistible Blue]

Assuming all your measurements were taken carefully, after haveing let the system run for a bit:

Your membrane is rejecting about 90% of the tds in the feed water - that's ok, assuming you have a 100 gpd membrane.

If you have a membrane of 75 gpd or less, you need to troubleshoot the membrane.

Yes - looks like its time for some new resin.

Doesn't look like your prefilters are clogged - are you near the chlorine capacity of your carbon block?