Extremely high phosphate from tap

[reefsnreefer]

so i Had a cyano outbreak after using my new RODI system. Tested the water I used and it was about .5ppm phosphate. Tested the tap here from the City and it’s over 10 ppm according to API tests. Is this even possible? Am I ever going to be able to get this water clear? It’s about 300ppm tds

 

[RandyC]

so i Had a cyano outbreak after using my new RODI system. Tested the water I used and it was about .5ppm phosphate. Tested the tap here from the City and it’s over 10 ppm according to API tests. Is this even possible? Am I ever going to be able to get this water clear? It’s about 300ppm tds

What kind of RO/DI unit are you using and what kind and how many filters/carbon/DI resins do you have in it?

 

[LilElroyJetson]

so i Had a cyano outbreak after using my new RODI system. Tested the water I used and it was about .5ppm phosphate. Tested the tap here from the City and it’s over 10 ppm according to API tests. Is this even possible? Am I ever going to be able to get this water clear? It’s about 300ppm tds

My tap water is about 300 tds because of the additives the city puts in the water (new building, new pipes), but I still get 0 tds out of RO/DI using a pretty cheap LiquaGen 4-stage Unit off Amazon. Do you have DI resin at the end of your unit? How long has it been since you changed the resin and/or filters?

 

[reefsnreefer]

i have the BRS 75 gallon per day 5 stage ro/di unit. i recently set it back up and only replaced the filters /di resin. after getting phosphate in the end water i replaced the membrane as well , and added two extra DI filters canisters (the double canister from BRS). So far no phosphate in my water anymore but i wonder how long these filter medias will hold up with such high concentration of phosphate to begin with.

 

[reefsnreefer]

to clarify, my inline TDS meter reads about 3 ppm before di and 0ppm after DI. after upgrading my TDS meter i can see its actually about .5 PPm TDS after DI and i assume thats ALL phosphate. (this was before i changed the membrane and added two more DI).

 

[RandyC]

i have the BRS 75 gallon per day 5 stage ro/di unit. i recently set it back up and only replaced the filters /di resin. after getting phosphate in the end water i replaced the membrane as well , and added two extra DI filters canisters (the double canister from BRS). So far no phosphate in my water anymore but i wonder how long these filter medias will hold up with such high concentration of phosphate to begin with.

Only time will tell, keep an eye out on that color changing resin. If you're concerned about using up media too fast, you could consider using a 3-stage DI resin setup, then you can change only the anion resin that's absorbing the phosphate as needed and not have to change the other resins as often (hopefully).

BRS discusses this setup at

 

[LilElroyJetson]

to clarify, my inline TDS meter reads about 3 ppm before di and 0ppm after DI. after upgrading my TDS meter i can see its actually about .5 PPm TDS after DI and i assume thats ALL phosphate. (this was before i changed the membrane and added two more DI).

I don’t know if I’d assume the .5 TDS is all phosphate without testing but a couple things to consider:

- if it’s your first time using it in a while, try flushing the first 2-5 gallons thru and then test the next batch
- could there be residue in the container you’re using from previous dirty water causing it to register .5 tds (which is pretty low and could show up from something as such, although we want as close to zero as possible. Personally, mine reads .2-.3 TDS on the Hanna meter and my water is fine.)
- is your TDS meter reliable/accurate and calibrated?
- finally, maybe .5 tds isn’t a big deal. If you test and it’s not phosphates, and there aren’t a ton of silicates in the water, I don’t see an issue as long as it doesn’t continue to climb. I use the Hanna silica checker to test for silicates. Just keep testing your water before you use it and you should be able to find out what’s going on if you run thru this checklist.

Good luck! Keep us posted!