Silly Question (TDS Reading)

[EmilyXLC]

So, as some of you may recall, I was given a 24 GPD Coralife RO Unit with a GE membrane that may or may not need a new membrane & filters. I decided to test it before immediately ordering anything (we let the unit run for 2 hours). I just tested the water & it said 64 PPM. It should be at 0, right?

Sorry, I've never done this before!

Thanks in advance!

 

[Chameleon]

replace the filters (sed/crabon) first and if that doesn't work then get a new ro membrane. ro membranes tend to last some time. you want a reading of 0 if possible

 

[EmilyXLC]

Okie dokie. I figured that 0 was ideal but you never know until you ask!

I've been surprised before.

 

[ritter6788]

Does it have a DI canister? If not then you may not get 0 TDS ever.

Single Deionization Canister - Bulk Reef Supply

 

[EmilyXLC]

No, it doesn't have a DI canister... yet. It will soon!

 

[jgraz]

If you getting 64tds on the filter water then I would just replace everything. Did you test your water before filtering. Curious what that reading is.

 

[Trex]

Yeah, need to know what the TDS of your tap water is.

64 is normally high post RO, but if your tap's TDS is 1000, then it isn't too bad.

 

[EmilyXLC]

I just tested my tap water, it's 116.

 

[Trex]

I just tested my tap water, it's 116.

That is a less then a 50% rejection rate from your RO membrane -- even the "cheap" ones will give 80-90%.
I would replace your pre-filter, carbon block and RO membrane (( at this point I suspect the membrane is shot )). Better off getting a quality RO membrane -- the 75 GPD Dow Filmtec one will give you a 96-98% rejection rate. With that membrane your post RO TDS would drop to around 3-6, which would be great. A DI chamber would bring you down to 0, which is where you want your TDS reading.

 

[jgraz]

I concur with trex.

 

[EmilyXLC]

That sounds like a plan, guys! I'm probably going to end up going with Spectrapure stuff if everything goes according to plan!