0.0 Phosphates even after dosing

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shawnt2011

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5 month old tank started with dry rock. I've been dosing neophos for almost 2 weeks with practically 0.0 readings on a Hanna within 24 hours. I just dosed 4.5ml in a 42 gallon tank and tested within 2 hours, 0.0. Am I going crazy or is this expected?
 
Out of curiosity, when you mix your sample for Hanna does it have any hint of blue? If it is clear you may have zero.

You can take some water out, spike it with NeoPhos and take measurement just to make sure Hanna is working. If you get the correct results you may need to dose more.

Your rock, sand, and surfaces balance out with the PO₄ in the water. If the water has none, they’ll absorb it up, and if the level drops, they’ll let some back out. Your system may have zero PO4.

Good luck,
 
It is clear even after the reagent 2 minutes shake and after the 3 minutes in the checker. Brand new reagent as well. What do you think could be an adequate safe dose in the system
 
If it is really 0, I would dose 0.1ppm and see where it is in a 24 hours.
Not sure how much NeoPhos you need to get 0.1ppm.
 
Could be all binding to rock. Feed a lot of pellets. Phosphates will go up
Unfortunately I'm trying to reduce food in the water column to get rid of digitate hydroids so I cannot do this and am trying to avoid nutrients from bottoming out.
 
I have to dose 35ml/day in my 60 to keep it at .06
 
That's good to hear. I dosed 8ml the other day and it only raised my phosphate to .028.. If I was shooting for a .1ppm I'd have to probably dose 32ml daily to get there. I may try a 16ml dose tomorrow AM and see where I'm at when I get home.
 
5 month old tank started with dry rock. I've been dosing neophos for almost 2 weeks with practically 0.0 readings on a Hanna within 24 hours. I just dosed 4.5ml in a 42 gallon tank and tested within 2 hours, 0.0. Am I going crazy or is this expected?
Are you testing with Hanna?
Dose 3 caps for a 3 days. Then test. Worst case you see .15 but that’s ok and manageable.
 
Yes Hanna. I dosed 9.0ml tonight and will test tomorrow AM and see where I'm at. I'll try to dose heavy depending on the reading and will see where I'm at in the PM.
 
5 month old tank started with dry rock. I've been dosing neophos for almost 2 weeks with practically 0.0 readings on a Hanna within 24 hours. I just dosed 4.5ml in a 42 gallon tank and tested within 2 hours, 0.0. Am I going crazy or is this expected?

It's normal for Phosphate to bind to carbonate surfaces.

Just keep going as you are.

Avoid doing large doses as large phosphate spikes and drops in the water column may well upset coral.
 
5 month old tank started with dry rock. I've been dosing neophos for almost 2 weeks with practically 0.0 readings on a Hanna within 24 hours. I just dosed 4.5ml in a 42 gallon tank and tested within 2 hours, 0.0. Am I going crazy or is this expected?
Cherish these early days of low phos. Before you know it the phosphate will unbind from your rock and make your reefing life hell!
 
I believe the neophos instructions tell you to test 24 hours later to see results, might be wrong though.
For almost 2 weeks I've been testing after 24 hours with a 0.0 result. I figured I'd test after an hour or two and see what showed up and 0.0 was the result.
 
I don’t know how I did that… 😎. I don’t think I can replicate it… while typing I had some technical issues 🙃 … maybe a glitch.
I have never been able to figure out how to do that, AND you're literally the only poster I've ever seen to do that, and I follow discussions on the Chem forum 🤣 🤣🙃

When you figure out what you did, please message me!
 
I believe the neophos instructions tell you to test 24 hours later to see results, might be wrong though.
For almost 2 weeks I've been testing after 24 hours with a 0.0 result. I figured I'd test after an hour or two and see what showed up and 0.0 was the result.
It seems to show up as soon as it mixes in. I test about an hour later and see the increase from it. My tank could go from .06 to zero in less than 24 hours. I’ve seen it happen when I was trying to figure out dosage.
 
Its going to take some time for the po4 to stabilize in your tank. It took almost 2 years in my system. Some weeks if dose and the next day read 0. I had to double up the neophos just to have any readable reading the next day. Some weeks it hold and other weeks it suck it up fast but it just took patience and lots of testing.

Dry rock and so called live sand bind up the po4 like crazy. Next time using the Hanna checker and if it reads zero after the reading just add a drop on neophos to the vile and it'll go blue instantly. If not then bad reagent.
 
Thanks everyone! Seems that maybe I was being too conservative with dosing. Reagents are fine as they turned blue when intentionally spiking the tester.
 

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