How do you know which RO System filter to change?

[Saltine]

Hey All

I've been using a 50gpd RO buddie for just about a year now, I've never swapped out the sediment, carbon or membrane cartridges, just the DI twice. Now it seems even with new DI my TDS is 001, how do I know what to replace? Start with sediment/carbon? Then membrane? It's cheaper to buy an an entire new kit than replace each filter individually. I guess this is why you monitor TDS from the membrane :O as well .

Thoughts?
Salt

 

[nervousmonkey]

You are correct; sediment filter and carbon. Sediment is simply a mechanical filter, only removing very large particles, so that one may be getting clogged.
Carbon filters are the chemical filtration; remove a lot of dissolved organic compounds, volatile organics, chloramines, chlorine, etc.
Although the carbon block is chemical in nature, it runs out of space for chemicals that adsorb to its surface. But it cannot filter out small ions, hence the need for a DI filter at the end.
RO membrane is what we all think of when we think of purifying water with the RO forced pressure filtration method.
So, if it's cheaper, it may be time to get an entirely new unit. o_O

 

[Saltine]

You are correct; sediment filter and carbon. Sediment is simply a mechanical filter, only removing very large particles, so that one may be getting clogged.
Carbon filters are the chemical filtration; remove a lot of dissolved organic compounds, volatile organics, chloramines, chlorine, etc.
Although the carbon block is chemical in nature, it runs out of space for chemicals that adsorb to its surface. But it cannot filter out small ions, hence the need for a DI filter at the end.
RO membrane is what we all think of when we think of purifying water with the RO forced pressure filtration method.
So, if it's cheaper, it may be time to get an entirely new unit. o_O

Alrighty, thanks!

 

[Brandon42]

You are correct; sediment filter and carbon. Sediment is simply a mechanical filter, only removing very large particles, so that one may be getting clogged.
Carbon filters are the chemical filtration; remove a lot of dissolved organic compounds, volatile organics, chloramines, chlorine, etc.
Although the carbon block is chemical in nature, it runs out of space for chemicals that adsorb to its surface. But it cannot filter out small ions, hence the need for a DI filter at the end.
RO membrane is what we all think of when we think of purifying water with the RO forced pressure filtration method.
So, if it's cheaper, it may be time to get an entirely new unit. o_O

Is it possible to simply rinse off the sediment filter than?

 

[AZDesertRat]

No
Replace the sediment and carbon every 6 months like clockwork. The sediment protects the pores in the carbon so it can adsorb chlorine and volatiles. Both of them protect the RO membrane which is the workhorse and does 90-98% of the work. Replace the membrane when it is no longer removing about 95-96% of the incoming TDS. Replace the DI when you no longer see 0 TDS.

What is your tap TDS, RO only TDS and final RO/DI TDS ? This tells you if the RO or DI or both need attention. You already know the sediment and carbon are 6 months past due and exhausted carbon may have allowed chlorine to melt the RO membrane.

 

[Saltine]

No
Replace the sediment and carbon every 6 months like clockwork. The sediment protects the pores in the carbon so it can adsorb chlorine and volatiles. Both of them protect the RO membrane which is the workhorse and does 90-98% of the work. Replace the membrane when it is no longer removing about 95-96% of the incoming TDS. Replace the DI when you no longer see 0 TDS.

What is your tap TDS, RO only TDS and final RO/DI TDS ? This tells you if the RO or DI or both need attention. You already know the sediment and carbon are 6 months past due and exhausted carbon may have allowed chlorine to melt the RO membrane.

Thanks! Would have loved to have known that, the "manual" just says "regularly" what the heck? lol

RODI 1-2 PPM
RO 15
TAP 152

 

[Saltine]

How do I tell if my membrane has melted?

 

[domination2580]

U can get filter replacement sets for like 60$ and its ussually a three year replacement kit....im pretty sure its cheaper to buy the filters than a new ro.

 

[Saltine]

U can get filter replacement sets for like 60$ and its ussually a three year replacement kit....im pretty sure its cheaper to buy the filters than a new ro.

Feel free to google it, with the RO buddie, seems to be cheaper to buy a new unit than 3 replacement cartridges.

 

[domination2580]

Feel free to google it, with the RO buddie, seems to be cheaper to buy a new unit than 3 replacement cartridges.

My eyes must have skipped over the ro buddie part lol. My appologies. I thought it was just a ro unit. So re-reading this yes u might be better off buying a new ro but thats going to get expensive every six months. I would save up and get a big ro system where u can change the filters for much less

 

[Saltine]

My eyes must have skipped over the ro buddie part lol. My appologies. I thought it was just a ro unit. So re-reading this yes u might be better off buying a new ro but thats going to get expensive every six months. I would save up and get a big ro system where u can change the filters for much less

Thanks!

 

[domination2580]

Thanks!

There are some for sale on the forum here. Check out some of the for sale posts on here. Either that or ebay

 

[Saltine]

There are some for sale on the forum here. Check out some of the for sale posts on here. Either that or ebay

Thanks! I'm looking now.

 

[AZDesertRat]

You can get a real reef quality RO/DI from Spectrapure for $125. No one can touch that.
Your RO membrane is not very efficient if the TDS is 15. My tap TDS is 560-650 and the RO only TDS is between 2 and 3. A DI cartridge lasts over year with a 100G and 16G reefs. You get what you pay for.

Don't buy a used system, 9 times out of 10 you are inheriting someone else's problem. Same with eBay, most are low end drinking water quality systems which are nowhere the same quality.

 

[Saltine]

You can get a real reef quality RO/DI from Spectrapure for $125. No one can touch that.
Your RO membrane is not very efficient if the TDS is 15. My tap TDS is 560-650 and the RO only TDS is between 2 and 3. A DI cartridge lasts over year with a 100G and 16G reefs. You get what you pay for.

Don't buy a used system, 9 times out of 10 you are inheriting someone else's problem. Same with eBay, most are low end drinking water quality systems which are nowhere the same quality.

Link?

 

[domination2580]

You can get a real reef quality RO/DI from Spectrapure for $125. No one can touch that.
Your RO membrane is not very efficient if the TDS is 15. My tap TDS is 560-650 and the RO only TDS is between 2 and 3. A DI cartridge lasts over year with a 100G and 16G reefs. You get what you pay for.

Don't buy a used system, 9 times out of 10 you are inheriting someone else's problem. Same with eBay, most are low end drinking water quality systems which are nowhere the same quality.

Debateable. Unless you have every ro systems exact details and have ran them yourself its impossible to say they arent good quality. No harm or pun intended.

 

[AZDesertRat]

Water treatment has been my profession for 38 years, there isn't much I am not familiar with.
Their membrane is operating at about 90% efficiency, (152-15 = 137, 137/152= .901, .901x100= 90% rejection rate which is nowhere near 98% where it should be. Something to keep in mind is for every 2% your membrane efficiency drops below that 98% your DI life is cut in half. So from 98% down to 90% your DI life is about 1/16th of what it could and should be.

Used systems are almost always in need of replacements so what appears to be a good deal gets expensive quick. Unless you know the person and the history of the system consider it as buying some empty housings and fittings, everything else is probably shot. eBay quality systems as a whole are completely different than true reef quality RO/DI systems, they are usually a drinking water system with coarse filters and a couple of dinky hollow horizontal tubes they call a DI filter. Not even close.
Check out www.spectrapure.com , www.buckeyehydro.com or www.purelyh2o.com and study the differences. Reef quality RO/DI does not have to be expensive but you need to know what you are buying.

 

[domination2580]

Water treatment has been my profession for 38 years, there isn't much I am not familiar with.
Their membrane is operating at about 90% efficiency, (152-15 = 137, 137/152= .901, .901x100= 90% rejection rate which is nowhere near 98% where it should be. Something to keep in mind is for every 2% your membrane efficiency drops below that 98% your DI life is cut in half. So from 98% down to 90% your DI life is about 1/16th of what it could and should be.

Used systems are almost always in need of replacements so what appears to be a good deal gets expensive quick. Unless you know the person and the history of the system consider it as buying some empty housings and fittings, everything else is probably shot. eBay quality systems as a whole are completely different than true reef quality RO/DI systems, they are usually a drinking water system with coarse filters and a couple of dinky hollow horizontal tubes they call a DI filter. Not even close.
Check out www.spectrapure.com , www.buckeyehydro.com or www.purelyh2o.com and study the differences. Reef quality RO/DI does not have to be expensive but you need to know what you are buying.

Agreed! As long as we do our research we should be fine is what your getting at? Ebay does have filmtec membranes.

 

[AZDesertRat]

Its not just the membrane. What protects that membrane? What are the micron ranges and are they nominal rated, near absolute or absolute rated? What is the DI resin and how is it configured? What membrane specifically is it, there are many that even Dow Filmtec makes that are not suited for reef systems. What flow restrictor does it have and what is the exact waste ratio? Does it come with an inline pressure gauge? Yoy rarely if ever find reef quality RO/DI systems on ebay, most of their vendors are out to make a quick buck, not to have a long term relationship with a reef hobbyist. Do your homework.

 

[domination2580]

Ok, this is why im asking these questions. Im trying to learn this. The way you put do your homework at the end made it sound like i was trying up you. Im not because yeah i dont know a lot about them. Is there any site that tells us that the reef needs that good quality of filters? I know its better but is it absolutely a must?