Phosphate testing new water?

[Reef.]

Anyone tried phosphate testing newly made salt water? Should it show a clear 0?

I have the Elos high resolution phosphate test kit, a 0 phosphate reading should be yellow but mine is more grey/blue which means phosphate is present, hard to tell at what lvl, maybe matches 0.092, definitely not yellow for 0, this is water I have made with new RO filters and resin, I’m thinking this is an issue? Anyone with the same test kit could try their new salt water and see if their reading is a clear yellow for me?

 

[PatW]

It should test 0. It could be the salt mix but I would think that any salt mix easily available would give 0 phosphate. So it could be that your water is the problem. I have a tds inline sensor on my unit so I know I am getting 0 tds water. My tap water runs at 0.3 ppm phosphate.

 

[Reef.]

No idea where it’s coming from, previous tests were low, since changing salt I’m getting high readings.

Tried tests with both Elos and salifert both show high readings on freshly mixed salt.

Could be my water but as said it was previously fine, I have just changed the filters on the RO unit also, so something is up.

Going to buy some distilled water tomorrow and make some salt water up with that, see what reading I get, hopefully that will help pin down where it’s coming from.