ro/di
- Thread starter rayn
- Start date
rkb
New member
From what I have ownen RO/DI units are all bacically the same. And in every case that I can think of the standard 10in cartridges are interchangable. So with that in mind just find the best price and go with it.
I do recommend purchasing a unit that either has two DI stages or purchase a second DI stage. The reasoning behind this is simple- most of us change out a DI cartridge when the TDS hits close to 2, some even sooner with a few that wait till around 5. At a TDS of 2 there is still some usable life left in the somewhat expensive DI cartridge. So what many of us do is run a system of rotating out DI cartridges like this- when the water out of the first cartridge reaches roughly half of the TDS of the water out of the RO membrane we discard the first DI cartridge and move the cartridge from the second DI unit to the first and place the new DI cartridge in the second DI stage. This rotation ensure a TDS of near zero all the time and you get a little more use out of your cartridges.
I do recommend purchasing a unit that either has two DI stages or purchase a second DI stage. The reasoning behind this is simple- most of us change out a DI cartridge when the TDS hits close to 2, some even sooner with a few that wait till around 5. At a TDS of 2 there is still some usable life left in the somewhat expensive DI cartridge. So what many of us do is run a system of rotating out DI cartridges like this- when the water out of the first cartridge reaches roughly half of the TDS of the water out of the RO membrane we discard the first DI cartridge and move the cartridge from the second DI unit to the first and place the new DI cartridge in the second DI stage. This rotation ensure a TDS of near zero all the time and you get a little more use out of your cartridges.
addicted2reefin
New member
air or oil dont matter. i prefer spectra pure ro/di. i feel there membranes have been much better ime. i have had my 90 gpd unit going strong for a close to two years with a 98% rejection rate out of the membrane.
also things to look at if u are "green" or eco friendly is high efficiency ro/dis which will be my next investment. for a "Normal" ro membrane to work the product:waste ratio is around 1:4. spectra pure claims a 1:.5(yes .5 as in 1 half.) idk much about them but its worth a look.
also things to look at if u are "green" or eco friendly is high efficiency ro/dis which will be my next investment. for a "Normal" ro membrane to work the product:waste ratio is around 1:4. spectra pure claims a 1:.5(yes .5 as in 1 half.) idk much about them but its worth a look.
rayn
New member
Okay added a air pressure guage and a laundry/garden hose adapter. All this for $152
rkb
New member
This is how mine shakes out- started with a Kent Marine Hi-S RO/DI but it has evolved.
Stage one- 1 micron sediment filter
Stage two- 0.5 micron carbon block filter
Stage three- 35gpd Hi-S RO membrane
Stage four- DI resin cartridge
Stage five- DI resin cartridge
this system also has a dual inline TDS meter installed after the RO stage and after the first DI stage. Plus, I have installed a RO flush kit to extend the life of my RO membrane.
The inline TDS meters are fairly good but to get a true reading of my product water I measure using a HM COM100 TDS meter set on PPM442.
In an attempt to recoup some of my waste water I have run the waste line to a 44g BRUTE. My freshwater and saltwater tanks are also both 44g Brute cans.
Stage one- 1 micron sediment filter
Stage two- 0.5 micron carbon block filter
Stage three- 35gpd Hi-S RO membrane
Stage four- DI resin cartridge
Stage five- DI resin cartridge
this system also has a dual inline TDS meter installed after the RO stage and after the first DI stage. Plus, I have installed a RO flush kit to extend the life of my RO membrane.
The inline TDS meters are fairly good but to get a true reading of my product water I measure using a HM COM100 TDS meter set on PPM442.
In an attempt to recoup some of my waste water I have run the waste line to a 44g BRUTE. My freshwater and saltwater tanks are also both 44g Brute cans.
Buckeye Hydro
.Registered Member
rkb
New member
Hi Russ-
The COM 100 came recommended to me from the guys over at the Reef Chem Forum and when I got it I set it to PPM442 as the enclosed literature said that 442 was "one" of the settings that would suit my needs. There are so many settings on the COM100 and honestly I don't really understand any of them ;-)
Recently, I asked in a thread what the reasoning is behind using PPM442 and one if the members of whom seems well respected replied with this-
This is a more real number than what most use and a more true TDS of your water. Most TDS readings are to low, by ~20- 25 % as they use NaCl and not 442
This was answer was good enough for me and I really didn't ask any further questions. One thing that I would ask you as the HM guy- I guess the COM100 is a much more sensitive device than the HM Inline monitor that is also installed and that accounts for the differences in the readings?
Thanks
Russell
Buckeye Hydro
.Registered Member
Yes. Also - the other HM products (as well as other meters) use the NaCl scale.
Additionally, the inline meters adjust the reading for air temperature, rather than water temperature as the handhelds do. If precision and accuracy is what you are after, go with a handheld. If it is convenience you're hunting for, it inlines will scratch that itch.
Russ
Additionally, the inline meters adjust the reading for air temperature, rather than water temperature as the handhelds do. If precision and accuracy is what you are after, go with a handheld. If it is convenience you're hunting for, it inlines will scratch that itch.
Russ
rkb
New member
Thanks for more insight on the difference in TDS meters, I really appreciate the explanation.
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