What are TDS Ideals?

[spartanph]

I've been purchasing RO water from my LFS but recently have been seeing alot of diatoms. They show up about 1 week after water changes.
I use RO water from my home RO system for top offs.
I decided to take a sample of my home RO water to the company I purchased my RO system from thinking that my filters may need changing.
My home RO water tested at 40ppm which they said is great but I'm thinking that is probably high.
They also claimed that DI is bad for saltwater tanks because it removes to many trace minerals. At this point my trust level was very low with their opinions so I decided to ask here.
What should TDS be for RO water and what about RO/DI? And is there any truth to their thoughts on the DI unit?
I'm going to pick up a TDS meter so that I can "see for myself" what the levels are and test my LFS water.

 

[mandarin w]

That is not the way we do it around here. RO/DI is very important. we run both. You want your reading not to be above a 5. But you really want to shot for zero - 2. If it hits 5, time to change out the filters. I don't know the why's. When I joined the Saltwater hobbist club in our area, that is the way they taught me. And as far as I can see, most of the other clubs I visit with, or meet people in, That is how they do it. So some one could probly tell you the whys.

 

[beth]

zero is your target, especially with inverts present. That should be the goal. 40 is way to much. You need to change your filter. Is your RO made for the hobby, or is a home depot variety?

 

[skywatcher]

My Typhoon RO/DI measures 8ppm from the RO and 0ppm from the DI. Sounds like your filters/membrane needs changing.

 

[cgrant]

i also have the typhoon and get 4 ro and 0 ro/di
I think 40 seems a alittle off, if this is a new system then something might be wrong?
If its a older unit then you prob need to change filters like they have already mentioned.
is this a new system or old? Sounds like maybe an old?

 

[rresper]

Hello,
Is a three stage filter all you need for a salt water system?

 

[cgrant]

most i have seen are 5 or 6 stage, i have the airwaterice typhoon (5 stage) and it works great!

 

[beth]

I agree that airwaterice brand works very well. I have one myself! And its afordable.

 

[spartanph]

My RO unit was purchased years ago with my water softener. It is a 6 stage filter but I haven't changed the filters out for about 18 months. I figured I was over due and that is why I questioned the response of the people at the place I purchased it.
Beth why would the unit need to be made for the hobby?

 

[cgrant]

IMO...Dont "need to be made for the hobby" I think what she means is you want one with a di filter, if yours is a 6 stage you should have a di filter on it.
Make sure you have a di filter, Replace the filters and you should be fine

edit: if its one of those whole house units change the filter every 6 months, if your only using it to make drinking water and fish tank every year should work!
IMO...You are way overdue on your filter replacement!