how much tds is to much

[mookie]

i was trying to figure out why i have red slime algae so i tested my RO water.i have 5tds comming out of my RO unit and my 10g ato tank has a tds of 30-40.
is it time to change my ro membrane? the ro membranes are pretty expensive though, would i be alright just replacing the other cartridges and the DI?
is 5 tds rely somthing to be worried about or am i just bugging and this has nothing to do with the red slime.
also is it normal for tds to rise after sitting in the ato tank?

 

[vangvace]

I would change the DI and filter cartridges with a TDS output of 5 because your membrane should still be good. .

 

[mfisher2112]

Depending on the type of unit you have, and how many gallons of water you have run through the system, you may be able to backwash it.

I have a typhoon III from air water ice, and it has a backwash ability. My TDS rose to about 7 and I ran it on backwash for a couple of hours and it cleared it out. TDS back to 0. I test it regularly though, just to stay on top of it because I'm sure I will need a cartridge swap soon. Honestly, though, I've only had to replace the cartridges once, and I've been running the unit for about 2 1/2 years now.

If you don't have that option, then replacing the filtration and DI cartridges are the way to go. As vangvace said, your membrane should be fine.

 

[reeferwanabe]

are you testing your water from a glass or directly from bucket? makes a big difference some times.