RODI Question

Slickbaby · 10/25/2006, 09:33 PM

Hi guys,

I just recently purchased a Kent Marine Deluxe Hi-S Maxxima 60 GPD RODI unit and I got it in and all set up with the TDS meter and everything looks good. No leaks or anything like that. I've let it run for 2-3 hours and when I turn on the meter I've got 130ppm in the water going into the filter and 30ppm going out.

Is my water really that crappy, or is there something wrong with the filter? Or maybe the meter?

Any help would be appreciated! Thanx!

mcurl98 · 10/25/2006, 09:43 PM

you should run about 5 gallons through it before testing or using-which I assume the 2-3 hours did but sometimes they run a little slow at first-or can run slower in cold weather. I assume you calibrated the meter? My water is about 330 going in and 0 coming out-so your water isn't that crappy. If your meter was properly calibrated, I'd let it run longer and test again.

Slickbaby · 10/25/2006, 09:49 PM

Hmm...how do you calibrate the meter? All there is on it is the on/off button and the switch for in/out.

Slickbaby · 10/25/2006, 09:54 PM

I just found out apparently that this TDS meter is factory calibrated and doesnt need to be recalibrated? According to Marine Depot anyway...

The meter is the HM Digital In-line Dual TDS Meter that came with the Kent RODI unit.

AZDesertRat · 10/25/2006, 10:31 PM

In lines are not very accurate due to the fact they are not really temperature compensated. Unless your water temperature and air temperature are exactly the same it will be off. I would recommend buying a HM Digital COM-100 handheld if you want accuracy.

mcurl98 · 10/26/2006, 12:10 AM

I've never heard of the need for temperature compensation with a TDS meter but I'm certainly no pro. I will tell you that my readings are the same (0) coming fresh out of the filter and after having sat in the barrel for a day or so. In any case, I think it would be unusual for a new set up to not filter it down to zero or close to zero. I would try to run it a bit longer and verify it was installed correctly-some new filters can spit out some carbon for a while-not sure about with a solid block though.

Slickbaby · 10/26/2006, 12:52 AM

ok I'll run it some more and post back here if I dont see any changes.

Thanx everyone!

AZDesertRat · 10/26/2006, 08:17 AM

Temperature compensation is critical to accurate measurements. Hand held meters have the temp probe built in to the end you dip in the water. Unfortunately the inline type have it in the fat portion of the plastic probe inside the little hole you see so they measure air temp and not water temp.

Slickbaby · 10/27/2006, 05:38 PM

Well what the hell. The more I run, the more the readings become the same. Now the input is about 107ppm and the output is about 75ppm. What the heck is going on!?!

Temp difference is about 10 degrees difference (ambient vs water)

Slickbaby · 10/27/2006, 05:54 PM

Hmm apparently I didnt read the directions carefully enough and did not run the first 10-15 gallons without the DI canister installed. So now the question is do I just continue to run it and all will be fine, or did I ruin the DI canister and should I go buy another one?

mcurl98 · 10/27/2006, 08:34 PM

the DI is fine. Just keep running it for the full time period. Assuming everything else was done right, it all should work out. I'd keep the DI cartridge full of water when you have it off. and, I'd read the directions again!lol

AZDesertRat · 10/27/2006, 09:24 PM

Test the RO only TDS and see how it compares to the DI and the tap water. If you don't have a bypass or way to test it just remove the DI cartridge and test the output without it in place.

10/25/2006, 09:33 PM	#1
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	RODI Question Hi guys, I just recently purchased a Kent Marine Deluxe Hi-S Maxxima 60 GPD RODI unit and I got it in and all set up with the TDS meter and everything looks good. No leaks or anything like that. I've let it run for 2-3 hours and when I turn on the meter I've got 130ppm in the water going into the filter and 30ppm going out. Is my water really that crappy, or is there something wrong with the filter? Or maybe the meter? Any help would be appreciated! Thanx!

10/25/2006, 09:43 PM	#2
mcurl98 Premium Member Join Date: Mar 2006 Location: san jose, ca Posts: 615	you should run about 5 gallons through it before testing or using-which I assume the 2-3 hours did but sometimes they run a little slow at first-or can run slower in cold weather. I assume you calibrated the meter? My water is about 330 going in and 0 coming out-so your water isn't that crappy. If your meter was properly calibrated, I'd let it run longer and test again. __________________ -Matt Current Tank Info: tankless

10/26/2006, 12:10 AM	#6
mcurl98 Premium Member Join Date: Mar 2006 Location: san jose, ca Posts: 615	I've never heard of the need for temperature compensation with a TDS meter but I'm certainly no pro. I will tell you that my readings are the same (0) coming fresh out of the filter and after having sat in the barrel for a day or so. In any case, I think it would be unusual for a new set up to not filter it down to zero or close to zero. I would try to run it a bit longer and verify it was installed correctly-some new filters can spit out some carbon for a while-not sure about with a solid block though. __________________ -Matt Current Tank Info: tankless

10/27/2006, 08:34 PM	#11
mcurl98 Premium Member Join Date: Mar 2006 Location: san jose, ca Posts: 615	the DI is fine. Just keep running it for the full time period. Assuming everything else was done right, it all should work out. I'd keep the DI cartridge full of water when you have it off. and, I'd read the directions again!lol __________________ -Matt Current Tank Info: tankless

10/25/2006, 09:49 PM	#3
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	Hmm...how do you calibrate the meter? All there is on it is the on/off button and the switch for in/out.

10/25/2006, 09:54 PM	#4
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	I just found out apparently that this TDS meter is factory calibrated and doesnt need to be recalibrated? According to Marine Depot anyway... The meter is the HM Digital In-line Dual TDS Meter that came with the Kent RODI unit.

10/25/2006, 10:31 PM	#5
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	In lines are not very accurate due to the fact they are not really temperature compensated. Unless your water temperature and air temperature are exactly the same it will be off. I would recommend buying a HM Digital COM-100 handheld if you want accuracy.

10/26/2006, 12:52 AM	#7
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	ok I'll run it some more and post back here if I dont see any changes. Thanx everyone!

10/26/2006, 08:17 AM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Temperature compensation is critical to accurate measurements. Hand held meters have the temp probe built in to the end you dip in the water. Unfortunately the inline type have it in the fat portion of the plastic probe inside the little hole you see so they measure air temp and not water temp.

10/27/2006, 05:38 PM	#9
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	Well what the hell. The more I run, the more the readings become the same. Now the input is about 107ppm and the output is about 75ppm. What the heck is going on!?! Temp difference is about 10 degrees difference (ambient vs water)

10/27/2006, 05:54 PM	#10
Slickbaby Registered Member Join Date: Feb 2005 Location: Denver, CO Posts: 89	Hmm apparently I didnt read the directions carefully enough and did not run the first 10-15 gallons without the DI canister installed. So now the question is do I just continue to run it and all will be fine, or did I ruin the DI canister and should I go buy another one?

10/27/2006, 09:24 PM	#12
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Test the RO only TDS and see how it compares to the DI and the tap water. If you don't have a bypass or way to test it just remove the DI cartridge and test the output without it in place.