Question about RO/DI

[Toddrtrex]

First, add the water to the bucket first, then the water -- it will mix better that way. Do you have a pump in there to mix the salt and water ? With having the salt in there first, I would let it mix for about an hour before testing it again.

As for how to test the TDS of just the RO water, (( assuming that your unit isn't already plumbed to have just an RO water spigot )) just detach the line that goes from the into the DI resin chamber. Those fittings look hard to get out, but they are actually very easy. The following picture should help (( should note, that this --- on my unit --- is where the clean water comes out of the DI chamber, but the concept is the same )). You can see the first white "ring" right after the tube, just push that in with your finger nail, and the tube will come free.

 

[Jerm77]

yes run the RO/DI unit with your tap fully open with cold water.

+1 on testing the water after the RO membrane without the DI. this will tell you if the DI is exhausted.

temperature of the water will not affect the TDS readings. but, it is possible your "hot" line has more minerals or contaminants present.

your RO "feed" length is not an issue, but it is possible that your waste line is not sized appropriately or could have the wrong sized tube.
- is your waste line coiled up at all ?
- how much waste water to feed water are you getting? most RO systems waste from 4-5 times as much as the feed water. for example, your system should waste about 4-5 gallons before you produce one gallon. this could be why you RO isn't removing as much of the minerals as it should.

it is possible that you will need to replace the carbon block, when water was left in the RO unit, many organics could have grown inside the unit. try flushing first before replacing.

 

[Samcorp]

My waste line is coiled up in the sink but water seems to be coming out of it fine. I'm getting a pretty good amount of waste water IMO but I haven't measured.

 

[Samcorp]

I checked the RO water only (without the DI resin) and I still got 20 PPM. The DI resin is the chamber which has color, correct? In my chamber its about 40% pink and 60% black/purple.

 

[Toddrtrex]

Then it sure seems like you have to replace your DI resin --- I never trusted the color changing part of it, just go by what the TDS meter tells ya.

Since you are going to be ordering DI resin, I would think about getting a new carbon block and pre-filter if they are over 6 months old, or if you don't know the age of them. They should be changed every 6 months.

 

[Samcorp]

Wait, the DI CHAMBER seems to only have water go up to about 80% of it. Is that a RO/DI general issue or is it the DI resin's issue?

 

[Samcorp]

Could I just go with 18 PPM and let it be in my tank? I really don't want to spend any more time ordering and buying things. My parents are sick of me spending all this cash and thinking that it will work...

 

[Toddrtrex]

<a href=showthread.php?s=&postid=15369877#post15369877 target=_blank>Originally posted</a> by Toddrtrex
Sure 25-29 is better then 180, but should be getting 0, and you have no idea what is making up that 25-29.

<a href=showthread.php?s=&postid=15370578#post15370578 target=_blank>Originally posted</a> by Toddrtrex
It is fine that DI chamber is only half-way full.

 

[Samcorp]

Hmm. This is strange then, because the RO/DI was testing a TDS of 0 at the person's house with whom I bought it from. Why could this be?

 

[Samcorp]

If I decide to go the 18 PPM route, will I need to use a dechlorinater or is that not necessary? I have heard people with tap water that is less than 30 TDS and successfully run tanks because of this. Why would my situation be any different if I am running tap water with a RO/DI at 18 PPM?

 

[Samcorp]

Also, after pouring the water into my sump (acrylic, a bit scratched on one side) I found that the water still looked a bit blue from the scratched side but looked clear from the non-scratched side. Is this just an illusion? I really don't want "blue water" to be an issue. I don't think the water is actually blue, but i'm still not 100% sure..

 

[Jerm77]

there could be several factors at play here.


CO2 in your water supply could have prematurely exhausted your DI resin. there are ways to determine this. take a tap water sample put it in a clean glass or container, check the PH. next, aerate the water with an air pump and air stone if you have one for a good period of time(maybe 5-10 minutes). or just let it sit for a longer period of time. Next, test the PH. if the PH is the same, then you don't have co2 present in your water supply. if the PH is higher, then you do have co2 present.

not sure how long the RO/DI was sitting prior to you using it(with water sitting in it), so again, not sure if organics are the issue.

RO/DI units do have maintenance costs over time. And yes it will cost you more money. maybe you might want to consider just buying RO/DI water from your Local Fish Store and transporting it.

But, I would first recommend that you try some of the things others have mentioned here before stressing yourself over the cost of replacing these filters.

 

[Samcorp]

Hi everyone. My TDS is now at 17-18 PPM. When I bought my used tank I found in the box of supplies it came with a DI cartridge. It looks gray and different from the one on my ro/di. Could I use it and try if it works or not? I think its new, but i'm not 100%.

 

[Samcorp]

This is the picture of what they look like (From another person's build). It is gray and is called "aquarium pharmaceuticals" ion chamber.
It says that replace it when the chamber goes from green to blue-violet, and it seems only 20% of it is blue-violet at the moment. But I do not know how old it is (seems quite old) and I'm 95% sure theirs no water in it. I actually might not use it because it looks really junkie...

 

[Jerm77]

samcorp.

you have to test it. same as your current DI. then you will know if its bad or not.

 

[Samcorp]

I'm now thinking that my TDS meter is not calibrated correctly. I re read the manual and it said the top portion is not waterproof and before I used it I tried to wash the whole thing off with water so the salt would come off. I think this may have damaged the device, although whats weird is, the temperature portion of it is still very accurate...