i should have posted this a day or two, but i was busy.
i believe that I was trying to make rodi water Tuesday afternoon. i turned the unit on and looked at the tds meter: it read 888. It was probably higher. i tested it with the other probe i have and I got the same thing.
i have never seen TDS that high. How is that legal? I had to run it yesterday at 400-500. And today it was still at 400. I guess all i can do is order some more filters, haha.
Anyone else notice the same thing?
What type of meter are use using Bret??
Mine is about 32 ppm prior to the RO unit.
My AWI unit came with 2 probes. one measures the water coming into the unit and the other after the GFO/DI.
i had an ERR message. flicking the actual connections made it go back to zero. do you have a hand held meter, brett to cross check? how long have the filters been in the rodi? that number is not right, seems to me.has the di changed color? do you get 2 different readings, one pre di and one after di? you should! seems to me 888 is just off and may be a malfunctioning digital readout. why not 887.contact awi
Brett did you try pulling the battery out and reinstalling it may need to be reset also might just be low on voltage maybe the battery is low. It be hard to believe that your TDS is that high. With it reading thats high think you would be chewing your water instead of drinking it.
Another question is how long has it been since you used the RODI unit? Maybe it needs ot be flushed?
If you don’t use them for a while bacteria wil strat to groq in the filters themselves and will cause unusually high TDS.
Same reason we don’t measure TDS in our holding containers - the bacteria are counted as TDS.
Organics and Biological contaminants like algae and bacteria have no electrical valance and therefore no effect on TDS meters.
[quote=“TimH07, post:7, topic:3749”]
Organics and Biological contaminants like algae and bacteria have no electrical valance and therefore no effect on TDS meters.[/quote]
They can break down and have an effect on TDS
And just to make sure I was right (I’m wrong often enough at home - just ask Lynn) - I sent the question to the Experts at Air, Water, Ice - here is there response:
Hello Craig,If it is an open air storage tank than yes it will. Bacteria dissolves in
water. It mighta ctually just be TDS creep in an open air container.If it is in a pressurized storage tank than no. The membrane should have
been able to remove all TDS before going into the tank.If you need anything else, please, don’t hesitate to contact us!
Best Regards,
Marissa Mele
Air, Water & Ice, LLC
Phone: 772-461-0256
Fax: 772-264-2778
sales@airwaterice.com
www.airwaterice.com
So if your storage container is open air (not a sealed system) then yes bacteria can grow, and affect TDS.
Thats new information to me, good to know!
But does the bacterial contamination adversely effect the purified water? I don’t think so. The impurities which would harm a reef aquarium would be filtered out. Bacteria use the contained environmental resources available to them for metabolism. If you added any nutrients into the filtered the water, I would say don’t use it.For aquarium use, the “false” positive TDS readings would be irrelevant.
Brett, if you don’t have it figured out by monday i can bring a handheld to the meeting for a double check.
Andrew I agree I don’t think the bacteria are causing any detriment to the tank in this situation. it’s just fresh water biological filtration taking place. I imagine there could be issues with amonia if the water was allowed to sit too long and metabolic breakdown occurred, but I think for the 5-10% water changes we do it shouldn’t harm anything.