High nitrates, low phosphates. What to do?

[BeejReef]

Wow!
Congratulations!! Hope everyone is healthy and happy

No more excuses. Just set your mind to testing all your major parameters whenever a baby wakes you up ;Joyful

 

[Randy Holmes-Farley Verified Community Expert]

So, I dosed a tiny amount last night. Something like 0.25ml. And checked my po4 when I got home (just a few minutes ago) and I’m measuring 0.02 on the Hanna ULR. I’m going to dose the same 0.25ml? Sound like a plan? Is anywhere between 0.05 and 0.1 my goal?

I've not read the whole thread yet, but you cannot dose phosphate and expect to get anything like the final value because nearly all of what you dose will be bound to rock and sand. Even with no consumption by organisms, if you want 0.02 ppm phosphate, you might have to dose way more than 10x that number to get a stable reading.

I also generally recommend DIY for nitrate and phosphate dosing because hobby companies often do not say what the product is or what purity it is. OTOH, it is cheap and easy to buy food grade products for nitrate and phosphate on line.