Poly storage tank P04

[JayRozzer]

Traced higher P04 levels back to my poly storage tank. I’m utilizing a Hannah ULR and I’ve checked everything a couple time.
Tank - .21
Freshly made salt water (water from tank) - .18
Ro/Di water from tank - .18
Ro/Di water straight from the DI plastic output tube -.03

This tank is supposedly food grade. etc. Any ideas? Water will sit in the tank for a week or two. If I need to replace any recommendations on what tanks (similar size) I should get?? Thx

 

[Pistondog]

Using this for 3 years now,

Maybe available in other sizes

 

[JayRozzer]

Using this for 3 years now,

Maybe available in other sizes

Looks like they are available in other sizes. I’d ideally like to find something that has a screw on/off top to add salt through.

 

[Pistondog]

Looks like they are available in other sizes. I’d ideally like to find something that has a screw on/off top to add salt through.

I cut a hole for the tunze ato pump. Easy enough.