What should RODI water PMs be...

fugetaboutit05 · Mar 17, 2021

Ive been getting RODI water from the LFS, at first i tested for just ammonia, but i can not for my life control or reduce the nitrate level in my tanks. Consistently reading around 30-45ppm.

Just picked up more RODI this weekend for water changes, and tested that for nitrates. Reading on the new water (pre- mixing step, no salt or equipment added) was around 40ppm, varying between buckets.

My question is, is this normal? Should i invest in my own setup? If so what equipment would you recommend?

Jekyl · Mar 17, 2021

fugetaboutit05 said:
Ive been getting RODI water from the LFS, at first i tested for just ammonia, but i can not for my life control or reduce the nitrate level in my tanks. Consistently reading around 30-45ppm.

Just picked up more RODI this weekend for water changes, and tested that for nitrates. Reading on the new water (pre- mixing step, no salt or equipment added) was around 40ppm, varying between buckets.

My question is, is this normal? Should i invest in my own setup? If so what equipment would you recommend?

Making your own is always best. I use the BRS 5 stage. It comes with a built in TDS meter. Will be cheaper in the long run.

Randy Holmes-Farley · Mar 17, 2021

RO/DI will have 0 ppm nitrate.

maybe your kit is not working?

fugetaboutit05 · Mar 17, 2021

Randy Holmes-Farley said:
RO/DI will have 0 ppm nitrate.

maybe your kit is not working?

I tested with 2 seperate kits, both saying the same thing. Registering high nitrates.

Started out with the API master saltwater kit, then moved over to the Red Sea Marine kit which I’ve been using ever since. The Red Sea kit showed it first, so i double checked it with the API

Mical · Mar 17, 2021

If your tests are accurate, I suspect your LFS has issues with their RODI water, +1 on @Jekyl suggestion - make your own RODI water. It'll pay for itself in a matter of months.

Randy Holmes-Farley · Mar 17, 2021

fugetaboutit05 said:
I tested with 2 seperate kits, both saying the same thing. Registering high nitrates.

Started out with the API master saltwater kit, then moved over to the Red Sea Marine kit which I’ve been using ever since. The Red Sea kit showed it first, so i double checked it with the API

This is fresh water you bought that purported to be RO/DI?

fugetaboutit05 · Mar 18, 2021

Randy Holmes-Farley said:
This is fresh water you bought that purported to be RO/DI?

No, i have saltwater aquarium displays. I mix my own tho. I buy the instant ocean sea salt 200lb box, and RODI from the LFS.

Randy Holmes-Farley · Mar 18, 2021

fugetaboutit05 said:
No, i have saltwater aquarium displays. I mix my own tho. I buy the instant ocean sea salt 200lb box, and RODI from the LFS.

Perhaps we are misunderstanding this sentence?

"Just picked up more RODI this weekend for water changes, and tested that for nitrates. Reading on the new water (pre- mixing step, no salt or equipment added) was around 40ppm, varying between buckets."

Aren't you saying the purchased RO/DI water had 40 ppm nitrate?

HuduVudu · Mar 18, 2021

fugetaboutit05 said:
Ive been getting RODI water from the LFS, at first i tested for just ammonia, but i can not for my life control or reduce the nitrate level in my tanks. Consistently reading around 30-45ppm.

Just picked up more RODI this weekend for water changes, and tested that for nitrates. Reading on the new water (pre- mixing step, no salt or equipment added) was around 40ppm, varying between buckets.

My question is, is this normal? Should i invest in my own setup? If so what equipment would you recommend?

Cities are starting to use chloromines to sterilize their water. This presents challenges to RO/DI units. You can see my build thread for my issues with it and my solution and another persons solution. Also there is much information available about it. BRS has done a pretty good series about it.

fugetaboutit05 · Mar 19, 2021

Randy Holmes-Farley said:
Perhaps we are misunderstanding this sentence?

"Just picked up more RODI this weekend for water changes, and tested that for nitrates. Reading on the new water (pre- mixing step, no salt or equipment added) was around 40ppm, varying between buckets."

Aren't you saying the purchased RO/DI water had 40 ppm nitrate?

Yes, the water i got measured in at 40ppm nitrates(varying between buckets +/-).... but i know that sometimes after mixing depending on the type of salt used the nitrates could increase that way, so i added in the comment that I measured the water prior to mixing stage. And prior to adding any equipment.

garbled · Mar 19, 2021

My tap water is high in nitrates. Not long ago I was a bad man, and didn't keep up on my RO/DI filter changes, and my RO/DI had nitrates too. If your filters (or in this case, their filters) aren't kept up to date, then it will get through, especially in areas with high nitrates. 40 seems crazy high though..

I would initially think maybe a bad test kit, I would hate to think that your LFS is doing a bad job of keeping up on the filters.

fugetaboutit05 · Mar 19, 2021

garbled said:
My tap water is high in nitrates. Not long ago I was a bad man, and didn't keep up on my RO/DI filter changes, and my RO/DI had nitrates too. If your filters (or in this case, their filters) aren't kept up to date, then it will get through, especially in areas with high nitrates. 40 seems crazy high though..

I would initially think maybe a bad test kit, I would hate to think that your LFS is doing a bad job of keeping up on the filters.

I’m with you on that thought process, but i am beginning to think that this may have been my issue all along with my nitrates. I CAN NOT get them down.

Like the saying goes... “ If you want something done right, do it yourself”

Looks like I’m going to be breaking down and setting up my own RODI system this weekend. Can’t help this weekly water change, but by next weekend i should have my own water to use. Unless i screw something up lol

Randy Holmes-Farley · Mar 19, 2021

Has your kit ever read les than 40 ppm? maybe it is a testing issue.

Shirak · Mar 19, 2021

Can you use a marine nitrate test kit on RODI? I thought not but ..

Have you tried testing after adding the salt?

garbled · Mar 19, 2021

Maybe buy some distilled water and try testing that. In theory that should read 0. To validate your test kit like Randy suggests. Or buy a different test kit, different manufacturer maybe? The problem isn't necc. that maybe your water is bad, but maybe that you can't trust your testing at all. If your testing is suspect, then you can't trust any readings on your tank itself, and the new RO/DI solves nothing.

fugetaboutit05 · Mar 23, 2021

Randy Holmes-Farley said:
Has your kit ever read les than 40 ppm? maybe it is a testing issue.

It has, in the very beginning, as the ammonia and nitrates went down, the nitrates began to rise. Normal cycling process.... but then I’m reading all 0’s and my nitrates are way up. The Red Sea kit comes with instructions to test if

Randy Holmes-Farley said:
Has your kit ever read les than 40 ppm? maybe it is a testing issue.

i had the same thought, thinking that a Marin test kit shouldn’t be used on on clear RODI.... but the other tests came back all 0’s(ammonia & nitrite)

monkeyCmonkeyDo · Mar 24, 2021

Whats the tds on the water? You have clean buckets or containers you are transporting in? I would get some ro water from the grocery store water dispenser. If its tds is lower and the trates are down...id let the lfs know.
Hths
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