Tds Question

[Kdocimo90]

I hooked up my Dual TDS Meter using one probe before the DI cartrige and one after... The one before is reading 1ppm while the one after is reading 0ppm.

Does this mean i have to replace everything before the DI cartridge right now?

[Kdocimo90]

bump

[Lenny718]

No. You should have low TDS before the DI and 0 TDS after the DI cartridge.

[Kdocimo90]

ok.. at what ppm of tds is it recommended to change the carbon block and micron filters?

[Lenny718]

I'm not a 100% sure and don't want to give you a wrong answer,maybe others will chime in.

[Kdocimo90]

lol ok thanks.

Its weird, the ppm went back down to 0.

[Kdocimo90]

bump

[IslandCrow]

I've never heard an exact answer to that question, though there is a formula out there somewhere for how long your DI will last with a particular TDS water going into it. The lifespan decreases quite rapidly for even small rises in TDS. The TDS coming out of my RO is usually between 0-1, so when it starts creeping above 5 or so, I replace mine. That may very well be too conservative, but I've only replaced it once in three years, so I don't think that's too bad.

Oh, and as a note, you will notice the TDS drop as you run more water through your RO. Mine actually starts around 40 or so when I first start things up (that's 40 coming out of the RO, but still 0 out of the DI). After a couple minutes, it's down to 1 or less.

[Kdocimo90]

thank you very much...

also, I turned the knob for cold water on my faucet about 3/4 all the way, and the hot water knob about 1/4 of the way.. should that be fine?

[rc02116]

<a href=showthread.php?s=&postid=13811666#post13811666 target=_blank>Originally posted</a> by Kdocimo90
thank you very much...

also, I turned the knob for cold water on my faucet about 3/4 all the way, and the hot water knob about 1/4 of the way.. should that be fine?

I thought you should use only cold water going through RO/DI system...

[Kdocimo90]

ok then i will keep it cold.. it only is coming out cold, i didnt want to mess with the hot knob any more

[Flipper62]

You do want to use cold water. If you have a clear DI housing, you will see the black carbon start to turn a orange color. AS it gets used up, the orange color will rise higher & higher. When it gets up to the top 3/4 area, you will start to see the TDS start to rise.

If you dont have a clear DI housing to see the filter, its going to be hard to tell. You will just have to trust the Meter.

If you dont have a clear DI housing, I would check with the MFG. & see if they make one.

http://i297.photobucket.com/albums/mm238/flipper62_photos/RODI-1.jpg

[Montezuma]

MIne has 3 chambers, I havent used it in awhile, and I tried today. Its reading 30 after it goes through the filters. Should I just change the orange/black canister only? Guess im no sure if I should replace all of them.

[Flipper62]

It really depends. Was there water in the filters. Its not a good idea to let the filters dry out.

IMO.....I dont care about the money to replace the filters. I have way more invested in the tank.

If your tank has been running, why haven't you been using the RO/DI unit ?

[Montezuma]

I was using my brothers who lives down the street. My tank is only 6 weeks old. I havent done any water changes. I was about to do one, but needed to check my TDS. Looks like its time to replace them all.

[Flipper62]

<a href=showthread.php?s=&postid=13812961#post13812961 target=_blank>Originally posted</a> by Montezuma
I was using my brothers who lives down the street. My tank is only 6 weeks old. I havent done any water changes. I was about to do one, but needed to check my TDS. Looks like its time to replace them all.

Well, If you are not sure. This is what I would do.

1 - Buy all new filters....This way you will know where you are. Start New..........Mark the filter change date on the canisters.

2 - Buy a COM-100 TDS meter. This way you can check the TDS any time you need to.

The COM-100 is only $50.00 from the FilterGuys.

http://www.thefilterguys.biz/tds_meters.htm

[Randy Holmes-Farley]

ok.. at what ppm of tds is it recommended to change the carbon block and micron filters?

The carbon and sediment cartridges have no impact on TDS, and TDS is not a measure of whether they need to be replaced. The sediment and carbon filter can be gauged by the pressure getting through them (if you have such gauges). Additionally, the carbon cartridge might need to be replaced before it causes a pressure drop, but mine never last that long.

[AZDesertRat]

The prefilter and carbon have little to no effect on TDS. TDS is total dissolved solids, small microscopic stuff that is electrically conductive in water. The prefilter removes TSS or total suspended solids, big stuff like sediment and particulates. You change the prefilter at 6 month intervals or sooner if you see a drop in pressure available to the RO membrane, its sole purpose is to protect the carbon block and membrane.
The carbon block is made up of billions of tiny pores which adsorb chlorine and volatile organic chemicals. It must be preceded by a good prefilter, prefferably of the same micron rating or very close so you do not plug those pores and render it useless. A 10 micron prefilter and a 0.6 micron carbon block is a no-no as the carbon is acting as a prefilter itself and will not last as long nor work as well. It also get replaced every 6 months or when you detect a chlorine break thru at the RO using a low range chlorine test kit. The 6 month rule is much easier! And ALWAYS disinfect the system when changing filters.
Always use cold water NEVER EVER try to blend or temper hot and cold water! Its the fastest way to ruin a membrane there is. Membranes cannot take water over 113 degrees. Remember being in the shower when someone flushed the toilet or started the clothes washer? You got scalded! Same thing happens to a RO membrane and its ruined.

You need 3 TDS numbers in order to know what to change, tap wate rTDS, RO only TDS and RO/DI or final TDS. The RO should be 96-98% less TDS than the tap water and the RO/DI should be 0 TDS. If the membrane has been stored for any length of time and has dried out it is possibly shot. Always use a RO at least once every 7-10 days, if not remove the membrane, place it in a zip lock bag with some water in it and store it in the refrigerator.