acanman
Well-Known Member
im thinking about getting the bulk reef supply build your own rodi. and was wondering if there units are good ro's? im thinking about going with the 4 stage with all the bells and whistles
ro di question
- Thread starter acanman
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Take a look at the units here, better prices and things like tested and guaranteed membranes and custom mixed DI just for reef applications make them a better deal. Plus they are a Sponsor of this forum and its nice to support the sponsors who support our hobby.
SpectraPure Customer Appreciation SALE! 20% - 50% off
The ProPlus at $149 includes and inline pressure gauge, dual inline TDS meter, batch tested 98+% 90 GPD RO membrane, 1 micron prefilter and carbon block, full size 20 oz vertical refillable DI filled with SilicaBuster resin and a capillary tube flow restrictor. Pretty hard to beat.
SpectraPure Customer Appreciation SALE! 20% - 50% off
The ProPlus at $149 includes and inline pressure gauge, dual inline TDS meter, batch tested 98+% 90 GPD RO membrane, 1 micron prefilter and carbon block, full size 20 oz vertical refillable DI filled with SilicaBuster resin and a capillary tube flow restrictor. Pretty hard to beat.
That is an old way of thinking. It used to be vendors used a 10 micron prefilter then a 5 micron and a 1 micron carbon block. The problem with that is the larger micron sizes allow particulates to pass through and foul or plug the pores in the carbon block rendering it useless for removing chlorine and VOCs.Todays lab tested methods are proven to be more efficient and cost less in the long run. Always use a prefilter the same micron rating or smaller than your carbon block so it does its job of protecting the more expensive carbon and allows it to do its job of removing chlorine. There is no need for multiple carbons as many still do, again its a throwback to the days when carbons were not what they are today. A single carbon block in the 1.0 down to 0.5 micron range is more than sufficient for tap waters containing up to 2 mg/L chlorine or chloramines and provides less head loss than two carbons.
Brad Syphus
Valuable Member
AZDesertRat, I have a quick question for you. I bought the 90gpd MaxCap RO DI system about 8 months ago and love it. I never read above 0 tds for about 5 months and then started reading 2-5 tds. At that time I changed the first 2 filters and it went back to 0. Now after a couple more months I'm reading about 5 tds. Should I go ahead and change all 4 of them out now, or just the first 2 again?
The MaxCap is a dual DI system. It has two dual inline TDS meters that read the TDS after the prefiter and carbon block (Left meter In position), post RO (Left meter OUT position), post MaxCap DI (right meter IN position) and post SilicaBuster DI or final RO/DI TDS (right meter OUT position).
First off the prefilter and carbon block have very little to absolutely nothing to do with TDS readings, changing them does nothing to reduce TDS. TDS is removed by the RO membrane and DI cartridges, the prefilter and carbon removes sediment or particulates (TSS or Total Suspended Solids- big stuff compared to TDS, Total Dissolved Solids, microscopic particles).
When you very first start to see any TDS on the right TDS meter IN position, which is the MaxCap DI cartridge, change the MaxCap cartridge which will then go back to 0 TDS. You should be able to exhaust 3 and possibly 4 MaxCap DI cartridges before you begin to see any TDS in the righthand OUT or SilicaBuster DI, final treated water. The MaxCap acts as a roughing or pretreatment for the SilicaBuster.
Change the prefilter and carbon block every 6 months like any normal RO/DI system or if you have a low range chlorine test kit (Spectrapure sells one for a few bucks) you can monitor the treated water for any signs of chlorine breakthru which is an indicator the carbon block is exhausted. You will also want to monitor the inline pressure gauge for excess pressure drop due to plugging or fouling of the prefilter which usually is not a problem.
Sounds like possibly you waited too long and your SilicaBuster is exhausted too but it should outlast 3 MaxCap DI refills or cartridges. All these directions are in the printed manual as well as on their site in the troubleshooting area.
First off the prefilter and carbon block have very little to absolutely nothing to do with TDS readings, changing them does nothing to reduce TDS. TDS is removed by the RO membrane and DI cartridges, the prefilter and carbon removes sediment or particulates (TSS or Total Suspended Solids- big stuff compared to TDS, Total Dissolved Solids, microscopic particles).
When you very first start to see any TDS on the right TDS meter IN position, which is the MaxCap DI cartridge, change the MaxCap cartridge which will then go back to 0 TDS. You should be able to exhaust 3 and possibly 4 MaxCap DI cartridges before you begin to see any TDS in the righthand OUT or SilicaBuster DI, final treated water. The MaxCap acts as a roughing or pretreatment for the SilicaBuster.
Change the prefilter and carbon block every 6 months like any normal RO/DI system or if you have a low range chlorine test kit (Spectrapure sells one for a few bucks) you can monitor the treated water for any signs of chlorine breakthru which is an indicator the carbon block is exhausted. You will also want to monitor the inline pressure gauge for excess pressure drop due to plugging or fouling of the prefilter which usually is not a problem.
Sounds like possibly you waited too long and your SilicaBuster is exhausted too but it should outlast 3 MaxCap DI refills or cartridges. All these directions are in the printed manual as well as on their site in the troubleshooting area.
Brad Syphus
Valuable Member
Thank you for the response.
I have all 4 of the replacement cartridges and will go ahead and change them all out.
One 1 micron prefilter and one 1 micron carbon block is better than 5 micron varieties, a 5 micron carbon has a useful life of about 3000 total gallons, thats only 600 gallons of treated RO/DI and 2400 waste gallons. A 1 micron carbon block has a useful life of 9000 gallons or 1800 good RO/DI gallons and 7200 waste gallons.
My presonal system uses a 0.2 micron pleated prefilter which has 10x the surface area of normal filters so is almost impossible to plug even though it filters many times better. I follow that with a single 0.5 micron 20,000 gallon carbon block. They have been in my system for 14 months now and I have no signs of chlorine breakthru and only a 2 psi pressure drop since new with no increase.
Smaller is better since it does not allow so much to get to the RO membrane, what does not hit the membrane does not have to be treated or flushed so you have a more efficient system.
My presonal system uses a 0.2 micron pleated prefilter which has 10x the surface area of normal filters so is almost impossible to plug even though it filters many times better. I follow that with a single 0.5 micron 20,000 gallon carbon block. They have been in my system for 14 months now and I have no signs of chlorine breakthru and only a 2 psi pressure drop since new with no increase.
Smaller is better since it does not allow so much to get to the RO membrane, what does not hit the membrane does not have to be treated or flushed so you have a more efficient system.
Make sure you disinfect the system while you have it down. Directions are on the Spectrapure site and probably in the manual although I don't remember.
No. Never use multiple prefilters or carbons unless you have specific known problems like high sediment loading, or unusually high chlorine. More is not better in this case, it actually hurts you as you end up with more pressure drop and les pressure available to the membrane. Lower pressure not only means lower GPD but also lower water quality since higher pressures make better water.
One single prefilter in 1 micron or less and one single carbon block in 1 micron or less and match the sizes as in both 1 micron or both 0.5 microns or make sure the prefilter is smaller micron rated than the carbon block so it does not have to act as a secondary prefilter.
If you have extra housings, replumb one to be a second vertical DI where you will get some bang for your buck. Dual DI helps you where dual prefilters or carbons often hurts you.
One single prefilter in 1 micron or less and one single carbon block in 1 micron or less and match the sizes as in both 1 micron or both 0.5 microns or make sure the prefilter is smaller micron rated than the carbon block so it does not have to act as a secondary prefilter.
If you have extra housings, replumb one to be a second vertical DI where you will get some bang for your buck. Dual DI helps you where dual prefilters or carbons often hurts you.
