How often do you change your RO/DI filters/membrane?

pammy · 12/03/2008, 10:33 AM

Hi. How often do you change your RO/DI filters and membrane?
I have a Spectrapure MaxCap 5 stage RO/DI with two TDS meters.
Both meters still show 0 TDS on the output. My tank is algae free, but the filters/membrane are 18 months old. Do most people change them out every 6 months? 12 months? Only when they start getting a positive reading on their TDS meters?
I have a 53 gallon tank with a 7 gallon sump and do 10% water change bi-weekly, plus top-off water, so I'm not filtering tons of water with a display/sump this size. I was thinking that as long as I have 0 TDS on the output of both meters, I'll wait to change the filters until the 2 year mark, unless things change and I start getting a positive reading on the TDS meters. 2 years seems like I might be pushing it though.

Thanks!
Pam

AZDesertRat · 12/03/2008, 09:27 PM

ALWAYS change the prefilter and carbon block every 6 months. If you use Spectrapures replacement prefilter in the 0.2 or 0.5 micron absolute rated sises and the 0.5 micron carbon block its not unusual for the RO membrane to last 8-10 years of heavy use.
The beauty of the MaxCap system is the life of the DI resins in both the MaxCap and SilicaBUster cartridges. My DI life went from 150 gallons with my old RO/DI system to 800+ gallons per MaxCap cartridge and 2500+ gallons per SilicaBuster cartridge. Thats here in Phoenix with a tap water TDS that exceeds 800 out of the faucet. Keep a close eye on the in probe of the right hand TDS meter which is the post MaxCap reading. It will be the first to show TDS and replace the MaxCap cartridge right away at that point. The SilicaBuster cartridge should last 3 MaxCap cartridges before it needs changing.
You must have great water!

pammy · 12/04/2008, 05:34 AM

Thanks AJ. My incoming tap water last night read 115 TDS. The max I've ever seen it at is 140. Guess it's really good compared to Phoenix. Bye
Pam

Quote:

Originally posted by AZDesertRat
ALWAYS change the prefilter and carbon block every 6 months. If you use Spectrapures replacement prefilter in the 0.2 or 0.5 micron absolute rated sises and the 0.5 micron carbon block its not unusual for the RO membrane to last 8-10 years of heavy use.
The beauty of the MaxCap system is the life of the DI resins in both the MaxCap and SilicaBUster cartridges. My DI life went from 150 gallons with my old RO/DI system to 800+ gallons per MaxCap cartridge and 2500+ gallons per SilicaBuster cartridge. Thats here in Phoenix with a tap water TDS that exceeds 800 out of the faucet. Keep a close eye on the in probe of the right hand TDS meter which is the post MaxCap reading. It will be the first to show TDS and replace the MaxCap cartridge right away at that point. The SilicaBuster cartridge should last 3 MaxCap cartridges before it needs changing.
You must have great water!

mga345 · 12/04/2008, 05:55 AM

Quote:

ALWAYS change the prefilter and carbon block every 6 months. If you use Spectrapures replacement prefilter in the 0.2 or 0.5 micron absolute rated sises and the 0.5 micron carbon block its not unusual for the RO membrane to last 8-10 years of heavy use.

If you have to change the prefilters every 6 months, can you use a cheaper prefilter (like 1 micron)?

mx270 · 12/04/2008, 06:21 AM

I change my 1 micron pre filter every six months and the carbon block every year. I didn't know they made a prefilter finer than 1 micron. Would a 0.2 micron filter be placed after the 0.5 carbon block????

A flush valve will extend membrane life.

AZDesertRat · 12/04/2008, 07:32 AM

Flush valves have not been proven to do anything other than lighten your wallet, there is not a single documented test with good results. Most are not used properly anyway and could never benefit you.
The 1 micron prefilter allows dissolved solids between larger than the carbon blocks 0.5 microns to pass through and lodge in the carbon block reducing its effectiveness. A carbon block is made up of billions of tiny microscopic pores which adsorb the chlorine and VOCs, if they are fouled or plugged they cannot do their job. Other vendors use graduated micron sizes and depend on the carbon to act as a secondary or third prefilter, this is not a good way to use carbon which is important in the protection of the membrane. Always use a prefilter the same micron rating or smaller than the carbon block for maximum protection and carbon life. The 0.2 micron ZetaZorb prefilter goes first. It is a pleated absolute rated filter so not only does it filter many times better it also lasts longer due to 10x the surface area of a normal filter. I have found in my own personal use it also does not cause any more and possibly less restriction than a 0.5 or 1 micron filter.
If you have a MaxCap system always use their recommended replacement filters or you have wasted your money on the hand tested membrane and hand blended DI cartridges, they will fail sooner. It takes the whole system, start to finish or prefilter to fianl DI to work correctly, its not just one or two pieces.

pammy · 12/04/2008, 07:40 AM

Have you found anyone that sells spectrapure filters that might off free shipping or any discounts?

Thanks, Pam

AZDesertRat · 12/04/2008, 07:44 AM

Spectrapure themselves offer Group Buy discounts but prices have risen so its not a huge savings anymore. The contact info is on their Sponsors Forum at the top of the page.
Marine Depot and Premium Aquatics both sell Spectrapure products as do a few others here on RC.

12/03/2008, 10:33 AM	#1
pammy Registered Member Join Date: Jan 2007 Location: New Hampshire Posts: 768	How often do you change your RO/DI filters/membrane? Hi. How often do you change your RO/DI filters and membrane? I have a Spectrapure MaxCap 5 stage RO/DI with two TDS meters. Both meters still show 0 TDS on the output. My tank is algae free, but the filters/membrane are 18 months old. Do most people change them out every 6 months? 12 months? Only when they start getting a positive reading on their TDS meters? I have a 53 gallon tank with a 7 gallon sump and do 10% water change bi-weekly, plus top-off water, so I'm not filtering tons of water with a display/sump this size. I was thinking that as long as I have 0 TDS on the output of both meters, I'll wait to change the filters until the 2 year mark, unless things change and I start getting a positive reading on the TDS meters. 2 years seems like I might be pushing it though. Thanks! Pam __________________ Pair of Ocellaris Clowns Flame Hawkfish Pygmy Angel Splendid Goby + Tiger Pistol Shrimp Current Tank Info: 53 Gallon Elos System 80 (31.5" x 19.5" x 19.5"), Elos NS500 Skimmer, Elos Planet 150w MH / 4 24w T5 Combo Light, CLICK on Pammy on the Left and then "VISIT Pammy's Homepage" to see my tank.

12/04/2008, 06:21 AM	#5
mx270 Registered Member Join Date: Nov 2008 Location: ohio Posts: 80	I change my 1 micron pre filter every six months and the carbon block every year. I didn't know they made a prefilter finer than 1 micron. Would a 0.2 micron filter be placed after the 0.5 carbon block???? A flush valve will extend membrane life. __________________ Today is the first day of the rest of your life! Current Tank Info: 125g reef

12/04/2008, 07:40 AM	#7
pammy Registered Member Join Date: Jan 2007 Location: New Hampshire Posts: 768	Have you found anyone that sells spectrapure filters that might off free shipping or any discounts? Thanks, Pam __________________ Pair of Ocellaris Clowns Flame Hawkfish Pygmy Angel Splendid Goby + Tiger Pistol Shrimp Current Tank Info: 53 Gallon Elos System 80 (31.5" x 19.5" x 19.5"), Elos NS500 Skimmer, Elos Planet 150w MH / 4 24w T5 Combo Light, CLICK on Pammy on the Left and then "VISIT Pammy's Homepage" to see my tank.

12/03/2008, 09:27 PM	#2
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	ALWAYS change the prefilter and carbon block every 6 months. If you use Spectrapures replacement prefilter in the 0.2 or 0.5 micron absolute rated sises and the 0.5 micron carbon block its not unusual for the RO membrane to last 8-10 years of heavy use. The beauty of the MaxCap system is the life of the DI resins in both the MaxCap and SilicaBUster cartridges. My DI life went from 150 gallons with my old RO/DI system to 800+ gallons per MaxCap cartridge and 2500+ gallons per SilicaBuster cartridge. Thats here in Phoenix with a tap water TDS that exceeds 800 out of the faucet. Keep a close eye on the in probe of the right hand TDS meter which is the post MaxCap reading. It will be the first to show TDS and replace the MaxCap cartridge right away at that point. The SilicaBuster cartridge should last 3 MaxCap cartridges before it needs changing. You must have great water!

12/04/2008, 07:32 AM	#6
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Flush valves have not been proven to do anything other than lighten your wallet, there is not a single documented test with good results. Most are not used properly anyway and could never benefit you. The 1 micron prefilter allows dissolved solids between larger than the carbon blocks 0.5 microns to pass through and lodge in the carbon block reducing its effectiveness. A carbon block is made up of billions of tiny microscopic pores which adsorb the chlorine and VOCs, if they are fouled or plugged they cannot do their job. Other vendors use graduated micron sizes and depend on the carbon to act as a secondary or third prefilter, this is not a good way to use carbon which is important in the protection of the membrane. Always use a prefilter the same micron rating or smaller than the carbon block for maximum protection and carbon life. The 0.2 micron ZetaZorb prefilter goes first. It is a pleated absolute rated filter so not only does it filter many times better it also lasts longer due to 10x the surface area of a normal filter. I have found in my own personal use it also does not cause any more and possibly less restriction than a 0.5 or 1 micron filter. If you have a MaxCap system always use their recommended replacement filters or you have wasted your money on the hand tested membrane and hand blended DI cartridges, they will fail sooner. It takes the whole system, start to finish or prefilter to fianl DI to work correctly, its not just one or two pieces.

12/04/2008, 07:44 AM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Spectrapure themselves offer Group Buy discounts but prices have risen so its not a huge savings anymore. The contact info is on their Sponsors Forum at the top of the page. Marine Depot and Premium Aquatics both sell Spectrapure products as do a few others here on RC.