015ppm ro water....what filters to replace?

[igotthatFIREman]

i just got a tds metter, im getting a reading of 015ppm. which filters should i be replacing? they are all about 3 month old and arent looking that good. where should i order my filters from and which ones do i need. i have probably made over 1000 gallons maybe.

[DSMpunk]

Do you have a DI chamber? If you do, you should replace that. I also replace the prefilters while Im at it (since they are so cheap)

Basically everything but the RO membrane itself.

[igotthatFIREman]

i dont no which filter is which....where is the best place to order them from? when it comes to ro units i no nothing... i only no wha the membrane is...

[AZDesertRat]

First off you need to know what you have, if its a RO unit or an RO/DI unit. What brand and model is it? Does it have a drinking water kit? Where did you sample from? Does it have a small final taste and odor carbon filter?
If its RO only, 15 may not be all that bad, if its RO/DI you need to do some further investigating.
In order to help us help you we need more TDS measurements. Take a TDS reading on your tap water first. Next take a TDS reading from where the RO water exits your unit, not from a pressure tank or drinking water faucet. Be sure to rinse the TDS meter well with RO or RO/DI water between each use so it does not become contaminated.
What are those readings?
Next if you have DI take a TDS reading from the combined RO/DI.

Answer those questions and we can help you before you go ordering a bunch of stuff that may not need replacing and will have 0 effect on final TDS.

[igotthatFIREman]

i tested the water strait from the ro/di into a cup and i got a 15ppm reading. my tap is close to 200. i do have di. i would rahter just replacing all the filters just to be safe since you say they are cheap. i have a coralife unit. where should i order from and what are the filters called? sediment, carbon, and di? what are the best ones for my unit? thanks for the help az!

[AZDesertRat]

Unless you have high sediment or high chlorine, the prefilter and carbon block should last 6 months. DI cartridges are entirely dependent on how well your RO membrane is functioning and how much water you have made.
Prefilters and carbons have very little to no effect at all on final TDS, they are there to protect the RO membrane.
Again, if you have a RO/DI you need 3 TDS numbers to determine what you need to replace.
1. Tap water TDS- not as estimate or approximation but the real deal
2. RO only TDS before or without DI- If you don't have a DI bypass then either remove the DI cartridge, run some water to fill the empty canister and take a reading or disconnect the 1/4" tubing from the RO membrane down to the DI canister and take a reading there. This is the most critical piece of information you need.
3. Finally take the RO/DI TDS.

If you are using a glass, make sure it is absolutely squeaky clean with no soap residue, water spots or film. I use a glass dedicated for just this purpose so it stays clean. First test the tap water TDS, triple rinse the glass and meter in DI water. Then test the RO only TDS and again triple rinse the glass and TDS meter in DI water. Finally test the RO/DI TDS and do a final triple DI rinse and put the glass away dry and upside down to keep dust and contaminants out of it. Always keep the cap on the TDS meter and remember to triple rinse with DI after every use so you don't ruin the probe.

Chances are you need a DI cartridge but without knowing how well the membrane is working its a guess. If the membrane is functioning correctly you should be seeing an RO only TDS in the 2 to 4 range. If that's the case you are adding contaminants back into you water due to exhausted DI resin and that's not good. The weakly ionized substances will release first and those include phosphates and silicates among others and you don't want those.

I would not replace anything until you get good reliable TDS readings from all three places to tell you what you need. No need in throwing money at it when it may not be the problem.

[igotthatFIREman]

ok first thing in the morning i will take all the readings. i will just unplug the last plug after the membrane and then it wont be di i dont think so i can take just a ro reading. im pretty sure the di is having alot to do with this 15ppm...

[AZDesertRat]

I agree but lets see how well the membrane is working too. Let it run long enough that the readings stabilize so you get past the TDS creep on start up.

[igotthatFIREman]

tap- 213ppm
ro/di-11ppm after it running for about 5 min
ro-8ppm


how is that...

[igotthatFIREman]

is the di chamber supposed to be full of water when running? because im not sure if it was before i unplugged it but now that plugged it back in it only has about 2cm of water in the very bottom...

[igotthatFIREman]

i turned the unit off and the water was about 3" high in the di chamber, i turned it on and the water in the di chamer lowered.....

[AZDesertRat]

The DI does not have to be full if its a vertical cansiter type, the water travels up through the center of the cartridge.
Sounds like your DI is exhausted so I would just remove the cartridge for now until you get a replacement. By continuing to use it you are doing more damage than good since it is already passing contaminants back to the treated water. Your RO could be a little better but its still not bad, it probably gets better the longer it runs too.

[igotthatFIREman]

what kind should i order? do i need a certain brand or size? im clueless. do they have it on dr foster and smith because im ordering salt from them soon

[igotthatFIREman]

also, what is the best way to clean my buckets out? im getting a higher ppm in the bucket that i use to put my ro water in and i just cleaned it out with the hose really good.

[AZDesertRat]

If you have a standard sized 10" vertical canister with a replaceable cartridge then most anywhere should have a replacement mixed bed cartridge. I really prefer dealing with people who sell and service RO/DI units as their core business though as they know what resin blends work best and they have a better turnover so cartridges don't sit on the shelf. Under the best of conditions DI resin only lasts about 6 months even when it is vacuum sealed.

For cleaning I use white vinegar either straight or cut 50/50 with water. Its pretty inexpensive so I usually use it straight. Muratic acid like you use for a swimming pool also works when you cut it like 20:1 but I don't like having or dealing with hazardous materials like that at home even though I do it all day long at work. Vinegar is less than $2 a galon and can be reused over and over when you strain it through a paint filter and re bottle it.

[igotthatFIREman]

http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=4501&N=2004+113776

is the mix bed cartrage at the bottom a good choice? it says Mixed Bed Resin Cartridge (for Maxxima RO/DI). i have a coralife 50gpd unit, does it matter?

[Thefilterguys]

AZ please I have worked very hard to dispell the unban myth on DI resin. Properly sealed resin and it does not have to be vacuum sealed has excellent shelf life. In the proper packaging and kept cool and protected from CO2 it will not go bad. I keep seeing this 6-9 month figure and it is so untrue.

Jim

[Thefilterguys]

<a href=showthread.php?s=&postid=10156159#post10156159 target=_blank>Originally posted</a> by igotthatFIREman
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=4501&N=2004+113776

is the mix bed cartrage at the bottom a good choice? it says Mixed Bed Resin Cartridge (for Maxxima RO/DI). i have a coralife 50gpd unit, does it matter?

Standard 10" cartridges will fit in your coralife housing and you just want to be sure your filters are high capacity.

Jim

[igotthatFIREman]

how can i be sure it is high capacity?

[Thefilterguys]

Buy your RO/DI products from a reef vendor your trust. I would recommend Matrikx +1 or CR1 carbon block filters and they will be good for six months at your current rate of water production. Beware of cheap drinking water filters as they are generally low capacity and rated for only about two thousand gallons including waste water. If your sediment filters are getting really dirty you may want to change them more often and either a 5 or 1 micron will be fine. A pressure drop is a good indication that your sediment filter needs changing.

DI resin or cartridges should be changed when you start seeing a reading of 2-3 in your DI product water. You don't want it to climb much higher as the resin will start throwing back stripped TDS and it will have an impact on your corals.

Jim

[AZDesertRat]

Jim the 6 month figure comes from Purolite themselves. I didn't make it up its what their Tech Support prople told me. Pass on whatever info you want but I beleive they are the authorities.

[Thefilterguys]

AZ Purolite resin may degrade faster but in most cases it is the meg ohm rating which goes down is my understanding. You see most companys state will produce 10 meg ohm water and may produce 18 meg ohm. The degrading is in meg ohm rating not in capacity to absorb TDS.

Jim

[AZDesertRat]

Jim when the megaohm resistivity goes down it means you do not have the capacity to attract TDS. As you can see in the chart here the difference between 18.2 megaohms and 10 megaohms is significant. When resindrys out and loses its electrical properties it does not work nerly as well, it does not stop at 10 megaohms it get worse and worse. No myth to it.
http://www.omega.com/techref/ph-2.html

[Thefilterguys]

Rat Purolite Resin NRW 37 which is a standard nuclear grade not premium, and many vendors seem to be selling, is rated at 10 MEG OHM FRESH FROM THE FACTORY.

I am say you are way overblowing how quickly packaged protected resin degrades. I am not saying many of the vendors are doing a poor job of packaging bulk resin and leaving it up to you to protect I have said that for years.