Po4 not decreasing despite a great deal of tm elimiphos rapid

[terrythenemo]

My 10 gallon nanotank has been struggling with high phosphate (Hanna checker: 0.32-0.90ppm) And I have been using elimiphos rapid over the past few months. I started with 1ml per day and gradually increased to 6ml per day (I have added 6ml every day for a week I know it’s a lot). However, with occasional fluctuations, my tank has now again ended up with 0.90ppm (the upper limit of Hanna checker). It seems to me elimisphos rapid isn’t working well in my tank. I have mainly soft corals and anemones in my tank with brown algae on most rocks and sandbed. My tank is 1.5 years old and is running floss and a skimmer. Two little fish in it and feed twice a day. Also adding 1ml of af elixir every day.
Should I still dose more elimis phos in this case?

 

[Randy Holmes-Farley]

It may take a lot because a lot of phosphate will be released back off any rock and sand in the tank.

Are you collecting the precipitated lanthanum phosphate?

 

[terrythenemo]

Thanks for replying! I am not running a strong skimmer so the waste in the collection cup is often yellow-ish. What would happen if i am not collecting the white precipitation? Will it dissolve and release back to the water? It usually disappears from the tank after like 15minutes.

It may take a lot because a lot of phosphate will be released back off any rock and sand in the tank.

Are you collecting the precipitated lanthanum phosphate?

 

[Randy Holmes-Farley]

Thanks for replying! I am not running a strong skimmer so the waste in the collection cup is often yellow-ish. What would happen if i am not collecting the white precipitation? Will it dissolve and release back to the water? It usually disappears from the tank after like 15minutes.

It probably won't dissolve, but if fine particles are still suspended in the water you test, it may detect the phosphate in those particles by dissolving them in the test.

nevertheless, I expect you just have to add more.