RO/DI purity level

[danskim]

I tested my RO DI water with a tds meter and it is 4ppm tds.
is this acceptable for reef use?

 

[Dr. Chek]

yes, I wouldn't be worried about that.
what RO/DI do you have?

 

[danskim]

just a 5 stage 100gph unit i got off ebay.

 

[Dr. Chek]

the reason I ask... just curious if it working at full effficiency.
I just picked the typhoon III and it put out 0 tds.... just make sure you replace your filters when advised to and you will be totally fine with 4ppm.

-james

 

[danskim]

ah i see, yeah i ordered new filters recently.

 

[Dr. Chek]

how old are those filters you have now? have you always had a tds meter? if so, what did the water measure when first setup?

 

[danskim]

i just got the tds meter yesterday.
i've had the filters for about 8 months but i haven't made more than 100 gallons with the rodi unit.

 

[dchao]

Re: RO/DI purity level

<a href=showthread.php?s=&postid=6521887#post6521887 target=_blank>Originally posted</a> by danskim
I tested my RO DI water with a tds meter and it is 4ppm tds.
is this acceptable for reef use?

TDS of 4ppm is acceptable, but it's indicating the final DI stage is not working properly, otherwise, you would have got zero TDS.

Therefore, you should also measure chlorimines at the DI output, chlorinmines are harmful to the fish.

 

[old salty]

When I read 3 or 4 ppm, I change the DI resin; this gets me back to zero where I like to be.

 

[danskim]

alright, i'll get some more di resin too!

 

[bureau13]

My kent RO/DI with all new membrane, prefilters and DI resin cartridge is measuring around 11 :-( I think I will recalibrate my TDS and cross my fingers, but I can't think of any reason for the water to not be perfect.

jds