Ro/di ????????

This is what I just got off of ebay

once again thank you all. well while i got deep into the research I found that spectrapure and purewater both use hm I think dual inline tds meter. I think i will go with the advance one that is out. this is it. Also are the handheld models that more accurate than the dual inline models?

 

Handheld TDS meters are superior to inline for a couple reasons. One is they are more accurate since they are temperature compensated unlike the inline that measures air temperature not water temperature. Another is the portability, you can use one meter to test the tap water, RO only water, RO/DI water, the neighbors water, your storage container, the LFS, the water store, bottled water etc. The inlines are dedicated to two points and cannot be used prortable, they depend on flow past the probe to work properly.
I own two of the dual inlines but rarely use them as the handheld COM-100 is so much better and never agrees with the inlines.

I would definitely replace the prefilter, carbon(s) and DI(s) but hold off on the membrane until you get some TDS readings, it might be OK and save you some money but the meter will tell.

Often buying a used RO or RO/DI ends up costing more than a new one when you consider all the things that need replacing and upgraded. Add up the cost of a membrane, prefilter, carbon(s)(I prefer a single carbon), DI resin or cartridges, pressure gauge, TDS meter etc. It all adds up quickly and a new reef quality system can be found complete for around $150 new and guaranteed.

 

You are correct!!!!!!!!!!!!!

After buying the replacement filters and the tds meter I probably was almost at a new one. Learning curve that can be very costly. I went ahead and bought the hm hand held com-100 also. I will check the tds reading from the inline and compare it to the com-100 just for good measure. thanks for the great info.

 

The COM-100 is an excellent meter. Its more expensive than most but its also much more accurate and sensitive with its ability to read in tenths compared to whole digits for the others. For low range accuracy as with RO and especially DI water it cannot be beat.

 

I would definitely replace all the cartridges. I'm looking at your DI stage and it looks hosed. DI resin is generally green in color when it is new and will change to brown after it's been exhausted. By the looks of it, the DI has been exhausted for way too long. My guess is that the seller wasn't 100% honest with your regarding its usage and how much life is left in the current stages.
All things considered new, the water coming out of an RO/DI filtration unit is completely reef safe, meaning no other chemicals are needed. You may need to add some alk supplements to boost the buffering capacity though, since all the minerals in the water have been removed.

 

Is it color changing resin? I prefer non color changing as it produces higher quality water since it does not contain dyes.
No need to add buffers, RO/DI will take on the characteristics of whatever it is added to quickly.