Phosphate stuck at zero

andsbunting · Mar 18, 2023

Phosphates bottomed out

I have recently added some more acropora colonies arohnd 6" diametres and since then i have bottomed out on phosphates, i have started dosing brightwell neophos which should raise my phosphate by 0.03ppm a day of which i am sticll reading 0.00 on hanna test kit and salafert. Has anyone else come across this before? Any help would be greatly recieved, my acros are loosing colour with no phosphate.

Specs of tank

I have a 450 l / 100gal, using Reef mat 11200for filtration, ATO , dosing alkalinity and mag ever 2 hours ,brightwell neophos 12ml per day 4 days running , feeding sea weed through the day, pellets 3 times a day, shrimp 2x per day. I have 1x clown, 1 foxface, 1x bristle tooth tang, 1x bluethroat teiggerfish, 1 diamond goby, cleaner wrasse, 7x acropora colonies l, 6x bluefin anemones, 9 x acropora frags.

Alk 9.8- 9.9 very stable
Mag 1440-1450 very stable
Calcium - 500 -505 - stable but lowering 5ppm per day till its at 450
Ph 8.1- 8.2
Nitrate at 4.3 4.6 stable
Phosphates at 0.00
Temp 73.5

Garf · Mar 18, 2023

andsbunting said:
Phosphates bottomed out

I have recently added some more acropora colonies arohnd 6" diametres and since then i have bottomed out on phosphates, i have started dosing brightwell neophos which should raise my phosphate by 0.03ppm a day of which i am sticll reading 0.00 on hanna test kit and salafert. Has anyone else come across this before? Any help would be greatly recieved, my acros are loosing colour with no phosphate.

Specs of tank

I have a 450 l / 100gal, using Reef mat 11200for filtration, ATO , dosing alkalinity and mag ever 2 hours ,brightwell neophos 12ml per day 4 days running , feeding sea weed through the day, pellets 3 times a day, shrimp 2x per day. I have 1x clown, 1 foxface, 1x bristle tooth tang, 1x bluethroat teiggerfish, 1 diamond goby, cleaner wrasse, 7x acropora colonies l, 6x bluefin anemones, 9 x acropora frags.

Alk 9.8- 9.9 very stable
Mag 1440-1450 very stable
Calcium - 500 -505 - stable but lowering 5ppm per day till its at 450
Ph 8.1- 8.2
Nitrate at 4.3 4.6 stable
Phosphates at 0.00
Temp 73.5

I’d probably just double the dose. Hanna checkers are not infallible, I believe the accuracy is only around 0.03 or so. I don’t worry about low phosphate however, mine is at 0.8 ppm, lol.

Seek&Reef · Mar 18, 2023

I've dosed .10 ppm daily when my rock was binding it all up. I was however testing daily before I dosed the next day. Did that for a month or so till it finally leveled out

vpierce3 · Mar 18, 2023

I dosed trisodium phosphate. It took a good 2 weeks for it to finally become detectable. Now it has stabilized and runs consistent. I still have to dose once a week or so.