How do I know when to change carbon filter, ro membrane, and di cartridge? I have a used spectrapure with dual ro membranes in series. I have an inline tds meter. After the dual RO stage it reads 9 and after the DI stage it reads 8. The carbon and sediment filters haven't been changed for quite awhile and are pretty nasty so I'm wondering if that's reducing the ability of the ro and the di stage or if the ro membranes and DI cartridge also need changed. I bought it used.
How do I know when to change carbon filter, ro membrane, and di cartridge?
- Thread starter thoeffe
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Sediment filter is cheap and the first line of defense for your membranes. Replace as often as needed so it’s visibly clean. Carbon filters have the life span listed on the label. You can estimate there. Color changing DI resin is the way to go. Replace membranes when you notice your TDS creeping up with all other filters nominal. The after DI should be 0 so something is up, likely DI media exhaustion.
Sediment filter is cheap and the first line of defense for your membranes. Replace as often as needed so it’s visibly clean. Carbon filters have the life span listed on the label. You can estimate there. Color changing DI resin is the way to go. Replace membranes when you notice your TDS creeping up with all other filters nominal. The after DI should be 0 so something is up, likely DI media exhaustion.
If you bought it used it's best to start with all new filters. The daily thread from yesterday has lots of good info. https://www.reef2reef.com/posts/9311478/
The bottom picture is sediment it's obviously bad.
Even if I do have to get all new filters and ro membrane, I still need to know how to tell which ones need replaced and which don't. Everyone is super vague about giving an answer. I don't just want to hear, "if it's used replace them all". I want to hear the reasoning behind it. Objectively not subjective answers. I'll need to know when to replace them the next time too.
Ok so here is what I do starting from new.
Sediment. I have 2. When first in line, turns brown or green then replace. Not a light shade but a darker shade. I place the old not so dark #2 in place of #1 and add a new one to slot #2. Sediment will clog all filters down the line.
Carbon. Depending on your water source (heavy metals and chlorine). If you have some chlorine in your tap water then go by the gallons the filter says it is good for. If you have a lot then I would replace at 1/2 that time.
RO: if the filter is a 98% rejection rated filter then if your filter is not rejecting 95% then its time to replace it. Chlorine will eat your RO membrane.
Resin. When it turns brown or out going tds is above 1 then replace.
There is no set time per say. Think oil change in a car. More you drive and in dirty hot conditions the more often you need to replace it
Sediment. I have 2. When first in line, turns brown or green then replace. Not a light shade but a darker shade. I place the old not so dark #2 in place of #1 and add a new one to slot #2. Sediment will clog all filters down the line.
Carbon. Depending on your water source (heavy metals and chlorine). If you have some chlorine in your tap water then go by the gallons the filter says it is good for. If you have a lot then I would replace at 1/2 that time.
RO: if the filter is a 98% rejection rated filter then if your filter is not rejecting 95% then its time to replace it. Chlorine will eat your RO membrane.
Resin. When it turns brown or out going tds is above 1 then replace.
There is no set time per say. Think oil change in a car. More you drive and in dirty hot conditions the more often you need to replace it
The reason behind replacing everything on a new system is so you start with a clean slate. You can continue to use up the filters if you wish that's a personal choice.so my di still has blue in it, isn't it supposed to turn completely brown before it's bad?
The bottom picture is sediment it's obviously bad.
Even if I do have to get all new filters and ro membrane, I still need to know how to tell which ones need replaced and which don't. Everyone is super vague about giving an answer. I don't just want to hear, "if it's used replace them all". I want to hear the reasoning behind it. Objectively not subjective answers. I'll need to know when to replace them the next time too.
As long as you monitor them all properly and have the correct equipment to monitor you can figure out when to change each stage and change as needed.
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