Finally got a TDS meter

[gutterguy]

I recieved my Hanna TDS1 today. I bought used off ebay $9 shipped . First questions are - it did not come with any calibration fluid. What and where do i get any? Can I use anything else to calibrate? How do I know it needs to be calibrated?

 

Also my tap water read 144 and my RO/DI is measuring between 000 and 001. When should I replace filters. My unit has been running since Sept 1.

 

Thanks

gg

[d9hp]

Should have arrived calibrated. Those readings sound good to me. Make sure you're using a sterile (rinse with RO/DI well) container.

 

I'd say you're at the perfect time to service your RO/DI system. New resin etc.

[paneubert]

Bulk Reef Supply sells little bottles of calibration solution. I bet you could also get some on Ebay. Just literally search for "TDS Calibration".

[gutterguy]

Thanks guys, and d, I bought it used so I was just wanting to make sure.

 

Thanks

gg

[d9hp]

One last thing...I've heard that when your output starts teetering between 1 and 0 you can get another week or two out of the resin by shaking the #### out of the canister...but I'm also the type of guy that scrapes the bottom of the peanut butter jar. Residual effects over my lifetime will probably save me a few dollars

[gutterguy]

Im the same way, mix a little water in the pasta sauce jar - good to go! also I just retested and made sure that I rinsed the cup I was using real good and got a 000 reading with no movement. I will be getting some new filters here soon, but makes me feel better that I am getting a 000 after 6 months

[AZDesertRat]

Once your DI starts showing anything other than 0 consistently its time for a resin change. The reason is DI resins start releasing weakly ionized substances even before it is exhausted and some of those contaminants like nitrates, phosphates and silicates may not register well at low levels on a hobbyist grade TDS meter.

Make sure you do your 6 month filter replacements, if you have had it since September you are coming up on the 6 month mark. Disinfect the system while you have it down, it only takes a few minutes and is well worth the time.

 

If your DI is a vertical canister and is packed properly, shaking it up will not do anything. If its a horizontal, take it off the top bracket and mount it vertically next to the vertical canister so it fills from the bottom up and you will get more life out of your resin since it will not be able to channel or short circuit like a horizontal which takes the path of least resistance.

[Coastie]

Once your DI starts showing anything other than 0 consistently its time for a resin change. The reason is DI resins start releasing weakly ionized substances even before it is exhausted and some of those contaminants like nitrates, phosphates and silicates may not register well at low levels on a hobbyist grade TDS meter.

Make sure you do your 6 month filter replacements, if you have had it since September you are coming up on the 6 month mark. Disinfect the system while you have it down, it only takes a few minutes and is well worth the time.

 

If your DI is a vertical canister and is packed properly, shaking it up will not do anything. If its a horizontal, take it off the top bracket and mount it vertically next to the vertical canister so it fills from the bottom up and you will get more life out of your resin since it will not be able to channel or short circuit like a horizontal which takes the path of least resistance.

 

2 questions, hopefully I am not threadjacking too bad but they are on topic.

 

1) I have a mighty mite sitting with all membranes horizontally. You are suggesting that I mount the mighty mite vertically to improve resin operation in the long run?

2) How do you recommend disenfecting? Bleach?

[AZDesertRat]

It would help the DI performance if you could stand it up so the DI fills from the bottom up.

 

The mighty mite uses throw away filters and has no 10" vertical housings so the disinfection directions really don't apply. For normal ful size units though here are some directions I have posted previously.

 

All vendors should provide disinfection directions with a new unit. I would check with your vendor. Basically it involves removing the prefilter and carbon(s), adding two tablespoons of regular unscented bleach, reinstall the empty housings, disconnect the line from the carbon up to the RO membrane so you don't get any bleach on the membrane then opening up the water supply to fill the housings. Let it sit about 5 minutes then open the supply again and flush it out until all smell of chlorine is gone.

When installing new the new filters after disinfection, or any replacements, flush the filters one at a time to remove all traces of antimicrobial treatments, glues, binders and carbon dust. Install only the prefilter first and flush it out the line you previously removed from the RO membrane. Next install the carbon and do the same flush. If you have two carbons then install the second one and do a flush before hooking back to the RO membrane. These steps will all extend the life of your membrane.