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Tarawa
11/13/2015, 11:28 AM
I purchased a 125g HDPE water tank, filled it up, which took a good while, I flushed it every couple of hours. I am aerating the water to use in DI, I also use the big container to fill the small 5g jugs. When I made DI water, I run a line from the 125g container into a booster pump then into the DI phases, tweaking the flow with a ball valve to slow it down.

That water read around 11 TDS. Now I emptied that tank, and I refilled it about a week ago, and went to make DI again for the aquarium, and the TDS was around 108. when I was making the water, the RO's output sensor was reading any where from 11-14 TDS. I've also tried taking some water from the tank and testing that as well, also I tried different probes, but all the same result.

So I ran the water thru the RO stages like I would if I was making more RO water, and sure enough after the TDS creep, stabilized at about 12 TDS. So what could have caused the water in the tank's TDS to go up by ten times? There is nothing I can see in it. I leave it covered. It also tastes fine. the it ate thru the remaining DI cart like it was candy (needed more DI for ATO).

Any recommendations?

Thanks.

SpectraPure
11/15/2015, 09:35 PM
I purchased a 125g HDPE water tank, filled it up, which took a good while, I flushed it every couple of hours. I am aerating the water to use in DI, I also use the big container to fill the small 5g jugs. When I made DI water, I run a line from the 125g container into a booster pump then into the DI phases, tweaking the flow with a ball valve to slow it down.

That water read around 11 TDS. Now I emptied that tank, and I refilled it about a week ago, and went to make DI again for the aquarium, and the TDS was around 108. when I was making the water, the RO's output sensor was reading any where from 11-14 TDS. I've also tried taking some water from the tank and testing that as well, also I tried different probes, but all the same result.

So I ran the water thru the RO stages like I would if I was making more RO water, and sure enough after the TDS creep, stabilized at about 12 TDS. So what could have caused the water in the tank's TDS to go up by ten times? There is nothing I can see in it. I leave it covered. It also tastes fine. the it ate thru the remaining DI cart like it was candy (needed more DI for ATO).

Any recommendations?

Thanks.

Hello. Is your container FDA approved free of BPA's? Also what are the tds readings on the system and psi? Typically DI degrades in containers after they are made. If your container is dumping off contaminates in the water it would cause the tds to increase.

Lets make sure that your RODI system is working perfectly first.

So the things that will help me diagnose this are below.

Tap water temp
TDS readings
Pressure reading on gauge

[email protected]

Tarawa
11/16/2015, 04:47 PM
It's not the maxcap180 thats acting up, tho; Water temp: about 6 or 7C. TDS at the tap: 1100-1200. Pressure: 60PSI w/ booster pump. I am making RO water at around 13TDS, and degassing it in 5g water jugs at the moment. I am not sure if the 125g container is FDA approved or not but it is that white HDPE. The first time I filled it the water was perfect sat at around 11TDS when I let it run thru the booster pump to remove tap water goo. What I am thinking might be the problem is: I built a degassing tower similar to what you have in one of your FAQs. After the tank was filled I changed the airline over to one thats in the tank, with an air stone on the end. There was still water in the degassing tower and it sat in there for a couple weeks. I am thinking that that un-moving water got kinda ucky. I ordered some silicone tubing and two more air stones for weight, and I'm going to fill the tank directly. I dont have the tank covered with its lid, I am using a towel on top just to keep dust and crap from settling into the water, on the assumption of; if I used the lid and drilled holes for the tubings. the CO2 wouldnt actually leave the tank, and O2 wouldnt get in via surface agitation.

SpectraPure
11/16/2015, 06:53 PM
I have a 2 station add-on that will recirculate your reservoir. It will keep the reservoir at the highest purity. You have to use your degasser tube with it. Basically it takes water RO water through two DI stages, and then it outputs it right back into the reservoir. It comes with a tds meter so you can monitor the reservoir water easily. It sounds like a better option than trying to degas the entire 125 gallons. One DI cartridge is a silica free, and the other is a Mixed Bed cartridge. It will solve your issue for sure!

Jeremy

Tarawa
11/18/2015, 05:16 PM
This add-on is two more DI carts? The water in the 125g container is RO water, used for making into DI, as well as drinking.

SpectraPure
11/19/2015, 01:15 PM
Do you automate your system on a white bobber mechanical float, or do you make large batches and then shut the system down? I didn't realize that you were using it for drinking water as well. In that case we wouldn't want to deionize the reservoir.

Jeremy

Tarawa
11/21/2015, 01:30 PM
I make a big batch, and then let the system sit till I need to make more water, which takes a couple weeks. When I need more DI I have ball valves to pull the water from the tank thru the booster pump and then thru the DI carts (letting the RO water rinse the pump out first)

I recently drained the tank, and got rid of the tower. The tank is almost full now and in my tests the water is around 15 TDS, which is just fine. Its a bit higher than the water coming from the RO filters, but I attribute this to the small amount of water I could not drain that was at 118TDS pushing the levels up a bit.

I have also modified the tank some what to shield it from any dust or anything that could get in, but not so much that gas exchange can not occur. We'll see in a week or so if the TDS is still in the 15 range.

SpectraPure
11/23/2015, 01:22 PM
Big batches are better! That is good that you follow that practice. I do have a dual float assembly that will automate big batches for you. 15 tds is remarkable for 1100-1200. Keep me posted on the progress.

Jeremy

Tarawa
11/24/2015, 09:06 PM
I have set up a float switch connected to an Apex controller that when triggered will close the RO water line and open the waste line via solenoids. Run like that for 30 minutes then power down the booster pump (need to buy another one to close the tap intake still tho =D).

I refilled the DI reservoir today, after letting the water degas for the past few days. TDS read anywhere from 11-15 when I checked in on it. So I figure something defiantly got in there. Or the standing water in the degassing tube got a bit gross. I also ran a PO4 test on the water just to be sure, used a tall thin tube and 4x'd the sample and reagents and that came out at 0.

SpectraPure
11/27/2015, 09:00 PM
the degas water could have been sitting too long. What is the tds coming out of the system?

Jeremy

Tarawa
12/11/2015, 02:18 AM
I just recently topped off my DI reservoir and it was around 12-13 TDS, still using the same water I filled it with on the 21st. Air pump still humming away into the tank.

SpectraPure
12/11/2015, 10:22 AM
You might need a new membrane.

Jeremy