RO DI PPM value
- Thread starter Jpurpz831
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condor
CORAL DR.
your membrane should last around a year or so when the tds creeps up to 5-10ppm
your sediment and carbon carts should be changed when they appear to get "dirty" but dont let them get too nasty cuz stuff will leach through and shorten the life of your membrane
your sediment and carbon carts should be changed when they appear to get "dirty" but dont let them get too nasty cuz stuff will leach through and shorten the life of your membrane
AquaWorldPSC
Well-Known Member
like 5-10 ppm change your filters. Talk about wasting money ha, in our store we have a aquafx great white r/o system (7stage (We added a extra sediment before the water hits the unit)) we change our sediment and carbon every 12-15 days. We are making about 300 gallons a day. The D/Is can get expensive for us to change too since there are 3 of them and it only lasts a week. The membranes only last about 2 months for us. :tire::tire: It's a big pain in the butt.
AquaWorldPSC
Well-Known Member
Oh and it has 3 membranes
OP
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Jpurpz831
Active Member
Holy ****
AquaWorldPSC
Well-Known Member
Yeah Holy **** ha we are currently looking for higher grade D/I cartridges if that is even possible. We are currently using all Coralife Cartridges (D/I, Carbon, Sediment)
AquaWorldPSC
Well-Known Member
But our tap water is bad it's about 280-300 ppm
dakotasreef
Prestige Worldwide
I have always heard, once it get to 7ppm it is time to change. My tap water is 420-470ppm tds. I can make about 100-150 gallons of water before my di is exhausted
AquaWorldPSC
Well-Known Member
Jeez and i thought our tap was bad
our local tap is around 400 if not higher, the store I usually grab my RO from has around a 18-30 TDS range--is this way too high?
AquaWorldPSC
Well-Known Member
Well you have to consider that the water can be stored for a few days which will add to the tds sometimes due to dead bugs, dust, and etc. Also the bucket that you use for transport can throw the tds off if you used to to acclimate fish or do water changes and don't clean it out good enough. When we test our customer's tds for them we recommend them to take it straight out of the r/o hose after the r/o system has been running for about 5 gallons then use a new dixie cup and fill it up then immediately put the lid on and bring it down asap.
this was being tested on the output line by an inline TDS meter
Prefilters and carbons have very little to absolutely nothing to do with final TDS readings so you cannot put a number such as 5-10 to it. The TDS (Total Dissolved Solids, key word here is dissolved, things that are roughly 0.0001 microns in size)is removed by the RO membrane and the DI resin. The prefilter and carbon block remove TSS or Total Suspended Solids, things like silt, particulates and sediment that are 1 micron and larger, and of course cabon adsorbs chlorine which can melt a membrane.
You change the prefilter and carbon every 6 months like clockwork regardless of usage to protect the RO membrane from damage. Another method is to use a pressure gauge and low range chlorine test kit and monitor the pressure drop and chlorine breakthru so you know when to change filters. Obviously the 6 month method is much easier and really 6 months is about the correct time period. You should also disinfect the system at that time so its serves a double purpose.
The membrane can last 18 months to as long as 10 years if you use high quality replacement filters and keep up with the maintenance. The DI resin is entirely dependent on your RO performance, how much water you make and if you have CO2 in your water. I have found through personal experience 16 oz of DI resin will treat between 3000 and 6000 total TDS before it is exhausted. That means if your RO only TDS is 10 and you have a standard 20 oz vertical DI you should expect to treat between 375 and 750 gallons of water before it is exhausted, its usually on the lower side.
You change the prefilter and carbon every 6 months like clockwork regardless of usage to protect the RO membrane from damage. Another method is to use a pressure gauge and low range chlorine test kit and monitor the pressure drop and chlorine breakthru so you know when to change filters. Obviously the 6 month method is much easier and really 6 months is about the correct time period. You should also disinfect the system at that time so its serves a double purpose.
The membrane can last 18 months to as long as 10 years if you use high quality replacement filters and keep up with the maintenance. The DI resin is entirely dependent on your RO performance, how much water you make and if you have CO2 in your water. I have found through personal experience 16 oz of DI resin will treat between 3000 and 6000 total TDS before it is exhausted. That means if your RO only TDS is 10 and you have a standard 20 oz vertical DI you should expect to treat between 375 and 750 gallons of water before it is exhausted, its usually on the lower side.
AquaWorldPSC
Well-Known Member
Yes we change our pre-filters alot since we are trying to protect our membranes. In about 12-15 days both of our sediment filters look like a copper pipes. We figure if it is getting that dirty that quick some of it must be getting to the membranes. Since there are 3 membranes on our system it was in our best interest to keep them maintained. Also like you said AZDersertRat the pressure gauge goes down as it gets dirtier.
Ricordea
Community Member
AZDesertRat
Here is a question for you being we are talking about TDS readings.
1. Have a in-line TDS meter
2.HM Digital Com 100
3.TDS3HM Digital (new)
How is it to get 3 different readings from all 3 meters?I have cleaned the high end Com 100. And I haven't use it that much.Yet testing it to the new 3HM different readings.You would think maybe a tad off or so.But not the case.I'm at the point not knowing which TDS is the right read out?Can you give me a clue?Why 3 TDS meters,the Com 100 I bought that one.The inline is use for the RODI.And the 3HM was a freebie at MACNA.
Here is a question for you being we are talking about TDS readings.
1. Have a in-line TDS meter
2.HM Digital Com 100
3.TDS3HM Digital (new)
How is it to get 3 different readings from all 3 meters?I have cleaned the high end Com 100. And I haven't use it that much.Yet testing it to the new 3HM different readings.You would think maybe a tad off or so.But not the case.I'm at the point not knowing which TDS is the right read out?Can you give me a clue?Why 3 TDS meters,the Com 100 I bought that one.The inline is use for the RODI.And the 3HM was a freebie at MACNA.
The inline will be theleast accurate of the three since it is not temperature compensated and actually senses air temperature and not water temperature.
What method are you using on the COM-100, I use ppm NaCl as it is the most aplicable for what we do. It should be very close to the TDS-3 if both are properly calibrated. I choose to calibrate my own since I am most interested in low range TDS such as RO and RO/DI TDS and less about higher readings like the tap water. Factory calibrations are often done with very high solutions.
TDS and EC Calibration Solutions - HM Digital
What method are you using on the COM-100, I use ppm NaCl as it is the most aplicable for what we do. It should be very close to the TDS-3 if both are properly calibrated. I choose to calibrate my own since I am most interested in low range TDS such as RO and RO/DI TDS and less about higher readings like the tap water. Factory calibrations are often done with very high solutions.
TDS and EC Calibration Solutions - HM Digital
Ricordea
Community Member
So your are saying that right out of the box,it's not meeting are tank needs.Because they are using ery high solutions.If so I never new this. I did talk to a water company that makes all of these filters that we used.I gave them my tests results.Being
Ricordea
Community Member
Oops sorry about that.
Being I'm on well water.Their theory was that Silica in the powder form is leaching threw the whole unit.Because of algae issues I'm having.A light fish load.feed once a day.Mention a cermanic or a absolute filter.I'm looking into the 0.2 last
Being I'm on well water.Their theory was that Silica in the powder form is leaching threw the whole unit.Because of algae issues I'm having.A light fish load.feed once a day.Mention a cermanic or a absolute filter.I'm looking into the 0.2 last
Ricordea
Community Member
Sorry man,this computer did this to me again !
As for being the last filter,before it hits carbon.I don't care how many prefilters a need to screen this sediment out.As long as it works.l Can silica bring on algae within the main system.What fall out does Silica do?If you have any other ideas LMK.That link you sent me doesn't work.But I know where to find them.
Back to these TDS meters.I didn't tests as often as I should.I nwould thing the readings would be ok.Do they change that quick.If that's the case.I'm sure a lot of people really don't reset their TDS.I'm included.
Thanks,Yea I finally finished it before it was was sent again.
As for being the last filter,before it hits carbon.I don't care how many prefilters a need to screen this sediment out.As long as it works.l Can silica bring on algae within the main system.What fall out does Silica do?If you have any other ideas LMK.That link you sent me doesn't work.But I know where to find them.
Back to these TDS meters.I didn't tests as often as I should.I nwould thing the readings would be ok.Do they change that quick.If that's the case.I'm sure a lot of people really don't reset their TDS.I'm included.
Thanks,Yea I finally finished it before it was was sent again.
doughboy
Well-Known Member
if its RO (and not RODI), then that is about right. RO membrane with 95 percent rejection rate will bring tds from 400 down to 20. Then the DI will take care of bringing it down to 0.
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