How often do you replace your RO membrane.

[Fishingandreefing]

I have the aquaticlife 100GPD twist in 4 stage rodi. My tap tds is about 145 and after RO is about 12 tds. (After DI is about 2-3 tds) I have heard that if it’s more than 5%, change it, do you do that? If so that the DI will last longer? (For my case 5% it’s 7.1)

It’s being a bit over a year and I roughly make about 50-60g rodi weekly with the booster pump.

thanks

 

[thedon986]

You can get inline TDS meters if you dont have some. One before RO, one after RO, one after first DI, one after second DI etc. Those will tell you when it's time to replace something. Sounds like you are definitely due, possibly for an everything replacement.

 

[Fishingandreefing]

You can get inline TDS meters if you dont have some. One before RO, one after RO, one after first DI, one after second DI etc. Those will tell you when it's time to replace something. Sounds like you are definitely due, possibly for an everything replacement.

Just the RO for now

 

[thedon986]

Just the RO for now

If your water coming out after the DI is not 0 tds, you need to replace those too.

 

[Fishingandreefing]

If your water coming out after the DI is not 0 tds, you need to replace those too.

If that’s the case, I prob have to replace my DI once a month. I usually change it if above 3 so usually about 3 months

 

[vetteguy53081]

When my TDS reaches 15 or annually, whichever comes first

 

[Fishingandreefing]

When my TDS reaches 15 or annually, whichever comes first

15? What your tap tds?

 

[vetteguy53081]

15? What your tap tds?

I’m at 2 but when it gets close to 5, not 15(typo)- I change it

 

[Fishingandreefing]

I’m at 2 but when it gets close to 5, not 15(typo)- I change it

Got you

 

[Opus]

Unless the twist in version isn't as efficient, you probably should change everything. Most RO membranes guarantee 95% rejection and most will do more like 97 to 98 when new. The RO membrane should last 5+ years. My tds is around 400 and it is around 5 after the RO membrane. My membrane is 3 or 4 years old.

Most people will say change the DI once you start reading tds because you have no idea what makes up that tds number. It might be nothing or be something that is bad for the tank or at least encourages algae growth.

 

[homer1475]

Haven't replaced the RO membrane in my unit in 5 years.

Still have 23 going in, and 1 out. DI last me a long time. lol

 

[Fishingandreefing]

Unless the twist in version isn't as efficient, you probably should change everything. Most RO membranes guarantee 95% rejection and most will do more like 97 to 98 when new. The RO membrane should last 5+ years. My tds is around 400 and it is around 5 after the RO membrane. My membrane is 3 or 4 years old.

Most people will say change the DI once you start reading tds because you have no idea what makes up that tds number. It might be nothing or be something that is bad for the tank or at least encourages algae growth.

You’re probably right, this aquaticlife twist in rodi unit is not the greatest. Ro membrane runs about $50 and I typically change it once a year. When it’s new, it’s rejection rate was about 95% if I recall correctly (7 tds) but now after a year its around 12 tds.

if your membrane can last 4-5 years, how much does it costs and what’s your tap water tds? I just want to compare it.

 

[Fishingandreefing]

Haven't replaced the RO membrane in my unit in 5 years.

Still have 23 going in, and 1 out. DI last me a long time. lol

23 tds from tap water? My tap water today was 145 and usually right around that.

 

[Fishingandreefing]

For all, if your membrane can last 4-5 years, how much does it costs and what’s your tap water tds? I just want to compare it.

 

[homer1475]

Yes 23 out of my tap. I live in a rural area with water that comes from springs in the mountains.

 

[Fishingandreefing]

Yes 23 out of my tap. I live in a rural area with water that comes from springs in the mountains.

Must be nice.

 

[Opus]

You’re probably right, this aquaticlife twist in rodi unit is not the greatest. Ro membrane runs about $50 and I typically change it once a year. When it’s new, it’s rejection rate was about 95% if I recall correctly (7 tds) but now after a year its around 12 tds.

if your membrane can last 4-5 years, how much does it costs and what’s your tap water tds? I just want to compare it.

My tap runs between 350 and 450. Looks like the exact membrane I have now is $73, it was around $60 the last time I bought it. You can get a 75gal membrane for around $42 and the 100gal is $51 at BRS.

 

[Fishingandreefing]

My tap runs between 350 and 450. Looks like the exact membrane I have now is $73, it was around $60 the last time I bought it. You can get a 75gal membrane for around $42 and the 100gal is $51 at BRS.

Nice. Unfortunately mine is the twist in type. Until I switch to the entire rodi unit but I will just stick with it for now.

 

[thedon986]

If that’s the case, I prob have to replace my DI once a month. I usually change it if above 3 so usually about 3 months

The aquaticlife systems are known to not be the best. I started out with one in 2016 and realized I was spending way too money on it. I upgraded to a Spectrapure Maxcap system I got a half off deal on. My tap is about the same TDS as yours and I've changed membrane and canisters once in 5 years. I use it to make homebrewing water, have a small 10 gallon and had a 100g system up for a year over that time. When I had my larger system up for about 15 months I was making 30-40 gallons a week as well.

If you choose to keep letting the TDS rise, I would consider some ICP tests every now and then to make sure nothing you don't want is in that 3 TDS. It could be a harmless 3 TDS or it could be something else building up.

 

[Big Smelly fish]

I make up a lot of water. During periods I’m raising seahorse fry I make up a few hundred gallons a week for months at a time. I have spectrapure 90 gallon a day and 75 gallon a day units. I tried other brands of DI media and have found spectrapure Di media to last longer than some of the other and especially compared to the media you pack yourself.