Phosphate Dosing Not Increasing Phosphates

[jacobc1199]

Hello all,
Recently i've been caught in a nutrient inbalance situation where my nitrates are high (16-32ppm) but my phosphates are always undetectable. Similar to others here my chaeto has been slowly dying and water changes never seem to help balance things out. I did some research and decided to dose phosphates with neophos. I dosed as per the instructions (for a 30 gallon ~5mL) daily for four days or so and never saw any changes on phosphate tests. I decided to add more than that dosage based on some other posts I read and started to add two or three times that amount 10-15mL per day and still didn't see a difference. I did verify that my test kits work and that the neophos is detectable when dosed into some rodi water. I'm really stumped here if anyone has any ideas. I do have some cyano in my tank but I cant imagine that it could uptake that much phosphate in a day.

 

[Mike N]

I think your tank is just thirsty for phosphate. When I was dealing with dinos, I was dosing both nitrate and phosphate and it took about a month straight of dosing before I had any detectable phosphate on Hanna meter. Keep up the dosing is my advice.

 

[SPR1968]

You really want to keep phosphate very low at less than around 0.03ppm or you risk all sorts of unwanted issues, and I personally wouldn’t be dosing any into the tank, if your feeding fish anyway.

You may need a more accurate test kit depending on what your using because 0.03 is very low.

 

[MJ in Boise]

Same issue here. 140gal system. Nitrates were around 12 before 5 weeks and 3-500ml bottles of neophos. Started with dosing .01 worth 3 times a day, ramped up to 6 doses of .01 per day. Tank just eats all the phos. Nitrates are now down to .75. Phos still undetectable each morning. Only adding .03 worth each day now. Any hope of retaining readable phos, or will I be stuck dosing forever?

 

[Randy Holmes-Farley Verified Community Expert]

Hello all,
Recently i've been caught in a nutrient inbalance situation where my nitrates are high (16-32ppm) but my phosphates are always undetectable. Similar to others here my chaeto has been slowly dying and water changes never seem to help balance things out. I did some research and decided to dose phosphates with neophos. I dosed as per the instructions (for a 30 gallon ~5mL) daily for four days or so and never saw any changes on phosphate tests. I decided to add more than that dosage based on some other posts I read and started to add two or three times that amount 10-15mL per day and still didn't see a difference. I did verify that my test kits work and that the neophos is detectable when dosed into some rodi water. I'm really stumped here if anyone has any ideas. I do have some cyano in my tank but I cant imagine that it could uptake that much phosphate in a day.

Your observation is normal and expected. Most likely, most of what you are dosing is getting bound to rock and sand.

keep dosing. Dose more. You will get there

 

[Randy Holmes-Farley Verified Community Expert]

Same issue here. 140gal system. Nitrates were around 12 before 5 weeks and 3-500ml bottles of neophos. Started with dosing .01 worth 3 times a day, ramped up to 6 doses of .01 per day. Tank just eats all the phos. Nitrates are now down to .75. Phos still undetectable each morning. Only adding .03 worth each day now. Any hope of retaining readable phos, or will I be stuck dosing forever?

You will likely need more P somehow, in foods or by dosing

 

[nano reef]

Did anyone resolve the o phosphate problem?

I had an imbalance of of 80 nitrates and 0.03 phosphates after I added a ton of frags at once and feeding reefroids. I then started nopox and got nitrates down to 2 but before nopox I was using chemipure elite so thats why my phosphates were low. Now phosphates are zero and have been dosing 5 ml daily neophos to a 36 gallon bowfront and no change. I even tested hours later thinking maybe consuming it fast but still 0.

After waterchange I had a crazy algae bloom that covered my back glass and wavemakers like a coat of green velvet! It was also on sand rocks and other glass but not as bad and those areas looked like diatoms. I assumed thats what it was until I read having zero could cause dino's. Plus supposedly dino's can come on hard after a water change so I have been dosing MB7 a few times and now Vibrant once per week plus neophos and feeding corals nightly and nitrates wont rise either but maybe 1 point. I think Its 3 now.

Whatever algae I have isnt typical looking for dino's because it isnt stringy or cyano because its green not red and slimy. I read if its cyano I should use chemiclean or something. So I dont even know if adding bacteria is the right way to go since I dont know what it is. Also they say that they help lower nutrients as well so maybe thats why my phosphates wont up! Nephos says if no change add a carbon source but a carbon source is what cause this low situation. Should I attempt to raise nitrates or leave that alone? Do I just keep on with neophos and bacteria or @Randy Holmes Farley is there a better brand of phosphates. Should I try chemiclean? I also have some patches of what looks like GHA Sorry I know this is a lot of questions but I guess the main question is raising phosphates because I dont want to get dino's If I havent already! .

 

[SMSREEF]

I dosed phosphates daily and was always close to 0 the next day or 2. I now add to my ATO.
I figured out what I add in a week and add it to my ATO, it is much easier.

also new rocks will soak it up, so at some point, I’m assuming the dosing will no longer be necessary once everything reaches equilibrium.

 

[Reefahholic]

IMO, tanks that have large colonies (especially Acropora) will consume N&P at rapid rates therefore resulting in zero readings. The color of the corals tells the real story.

If you do not have large colonies the PO4 could be reading low or zero due to other reasons Randy discussed above.

One thing to keep in mind is the test kit you are using. I’ve always used Hanna Phosphorus ULR for testing ultra low phosphorus levels. These low levels will not show up on some test kits. I like to run at 0.05 ppm to about 0.1 ppm PO4. This level is very low. This is why I use ppb (parts per billion) tester. 1 ppm = 1,000 ppb. So if I’m getting a reading of 30 ppb (which is 0.09 ppm) on my Hanna Phosphorus ULR...the regular Hanna Phosphate meter will read zero because it’s under the range for that meter. So you may have some low levels depending on what test you’re using that you just can’t see on that test.

Another thing to consider is the strength of the supplement you’re dosing. A lot of these companies make weak doses because they know that some reefers will nuke their tanks. I can tell you first hand from dosing PO4 to my system that if you mix the dose strong enough, you can see the result of 1 dose in any tank. It may be briefly for some heavily stocked tanks, but you can make it register on a ULR tester.