Phosphate question.

[salinity now]

My reef tank is 13 months old. I'm testing phosphate at API 0.25 and Hanna checker at 0.90. This can't be right, can it? No hair algae but a few diatoms on the glass that I scape off every day. I'm running two PhosGaurd packs in a 75-gallon tank that I change out every 4 days. Everything else is nominal.

 

[Garf]

My reef tank is 13 months old. I'm testing phosphate at API 0.25 and Hanna checker at 0.90. This can't be right, can it? No hair algae but a few diatoms on the glass that I scape off every day. I'm running two PhosGaurd packs in a 75-gallon tank that I change out every 4 days. Everything else is nominal.

I'd trust the Hanna. I had a similar variation when testing with anything other than Hanna.

 

[Mr. Mojo Rising]

I would not trust API test kit, better to throw it out rather than let it confuse you. i find that the hanna phosphate test is very accurate, if its done correctly.

 

[Dom]

My reef tank is 13 months old. I'm testing phosphate at API 0.25 and Hanna checker at 0.90. This can't be right, can it? No hair algae but a few diatoms on the glass that I scape off every day. I'm running two PhosGaurd packs in a 75-gallon tank that I change out every 4 days. Everything else is nominal.

I think you are throwing out your PhosGuard too quickly.

I started with 1 cup of PhosGuard in a reactor for a system that has 140-150 gallons of water volume. It lasted two weeks.

Monitor your PO4. If it continues to go down, the PhosGuard is still good. Once it starts tracking up, the PhosGuard is depleted and needs to be changed.

 

[salinity now]

I think you are throwing out your PhosGuard too quickly.

I started with 1 cup of PhosGuard in a reactor for a system that has 140-150 gallons of water volume. It lasted two weeks.

Monitor your PO4. If it continues to go down, the PhosGuard is still good. Once it starts tracking up, the PhosGuard is depleted and needs to be changed.

TNX will give that a try. Just put in two yesterday will monitor and advise.

 

[GARRIGA]

Hanna sometimes need re-calibrating. API not going to be precise but shouldn't be that off although reagent could have expired. Third test kit might be needed or perhaps take sample of that tested to LFS and get a third opinion.

 

[salinity now]

Hanna sometimes need re-calibrating. API not going to be precise but shouldn't be that off although reagent could have expired. Third test kit might be needed or perhaps take sample of that tested to LFS and get a third opinion.

I checked both regents 2027. Never bought any crap products from BRS. So will continue to monitor.

 

[GARRIGA]

I checked both regents 2027. Never bought any crap products from BRS. So will continue to monitor.

The API has a shelf life once opened. Another reason Hanna tend to be more precise. Oddly, when Hanna ran out of nitrate powder many used API and some auto testers do as well and why I say API may not be precise but shouldn't be that off either.

What I've found is how best to view API being from a top down as that makes comparing colors easier. This way regardless of light source all should reflect the same although viewing under full spectrum or sunlight best.

 

[CHSUB]

Hobby test kits are inaccurate and unreliable. If you do everything perfectly, Hanna is good.