Confused on phosphate levels and what if anything to do

[ID-Reefer]

Tank is 18 months old. Has been doing very well especially for past 6 months. Mixed reef, 250 gal system.

perameters
1.025
Ca 435 (Hanna)
Dkh 8.7 (Hanna)
N03 10 (Hanna)
Mg 1330 (apex)
P04 .23 (Hanna)
RODI water tests 0 with TDS meter.
AWC - 10% /week. 3.5 gal. Per day


Things have been very stable for months. Then this past week seemingly out of the blue my phosphates jumped up to .2. (I typically test my P04 and N03 1-2 times a week) P04 In the past been around .04 to .07. The only change I made a few weeks ago was to install a reefmat to replace my socks.

6 months ago my phosphates and nitrates were going up so I started dosing nopox. I started small and it was enough to keep P04 down. Ive been dosing around 3ml ever since. Now this sudden increase.

corals including acros all seem happy. No change in polyp extension. As far as I can see all corals seem fine.

I don’t understand the sudden change in phosphates. Same feeding regimen. So question is why and what if anything should I consider doing?

 

[Randy Holmes-Farley]

I don't think I'd work to lower the phosphate if everything seems good in the tank. Some great tanks have phosphate much higher.

 

[Reefnewb]

In a tank that nice i wouldn’t worry too much about it unless corals don’t look happy.

 

[EeyoreIsMySpiritAnimal]

How long has the phosphate reagent been open? Could it be that the test is wrong?

 

[ID-Reefer]

How long has the phosphate reagent been open? Could it be that the test is wrong?

The Hanna reagents are individually packed. So opened up right before the test.

 

[EeyoreIsMySpiritAnimal]

The Hanna reagents are individually packed. So opened up right before the test.

I did not realize that.

 

[ID-Reefer]

Its been about a week. Ive doubled my dose of no pox to 10ml / day. The P04 isn't budging and has gone up slightly to .26

I tested my AWC water just to be sure Im not putting in P04 with my water changes. It tested zero.

My nitrates are slowly dropping and as of this morning sit at 7.9.

Coral all still look good but Im getting worried that this high level of Phosphate and the imbalance of my N03 to P04 ratio is going to start a crash. As mentioned earlier I haven't made any changes to the system beyond the reef mat. Except I did remember one other thing - I took out some old bio media I had in my sump and replaced it with new ceramic bio filter bricks. Could these be leaching P04 into my system? I started my tank with Carib Sea Life rock... could that somehow be at fault?

Any thoughts? Should I increase the no pox dose again? I run a little GFO so maybe I should drop my no pox down to my usual dose and increase GFO? Or try another P04 reducer? I have a package of "Zenium" which is a Lithium Chloride pellet and supposed be great at reducing P04. Anyone use that before? https://www.getzenium.com

Thoughts?

 

[Miami Reef]

Nopox (carbon dosing) doesn’t do much for phosphates. It impacts nitrates more.

If you are set on lowering the phosphates, use a little more gfo than usual. If you are using the gfo in a reactor, you’d change the gfo when the output of the reactor’s phosphates start climbing back up.

 

[ID-Reefer]

Nopox (carbon dosing) doesn’t do much for phosphates. It impacts nitrates more.

If you are set on lowering the phosphates, use a little more gfo than usual. If you are using the gfo in a reactor, you’d change the gfo when the output of the reactor’s phosphates start climbing back up.

When I first started carbon dosing it seemed to drop my P04 fairly quickly and N03 slowly but now this...

I don't run a GFO reactor - just media bag in the sump and use a tiny bit (1/2 cup) of GFO so will increase that amount. Thanks for the suggestion.

 

[Jekyl]

Effects from NoPox don't happen quickly. It took a month of dosing before my numbers reflected it. As said above GFO or chemipure elite can help.

 

[Clownfishy]

Nopox (carbon dosing) doesn’t do much for phosphates. It impacts nitrates more.

If you are set on lowering the phosphates, use a little more gfo than usual. If you are using the gfo in a reactor, you’d change the gfo when the output of the reactor’s phosphates start climbing back up.

A lot of people have mentioned and experienced the same thing. I on the other hand always noticed my phosphate drop more aggressively than NItrates. Weird.

I would continue increasing NOPOX further but it goes without saying, increase gradually and test daily just in case you see a sudden drop.

 

[Tired]

Your phosphate is probably fine. Some people run up to 1ppm phosphate and have no problems, except that some corals may not have their best coloration. Chasing after an acceptable parameter and trying to mess with it is more likely to cause problems than having it at a slightly unusual level.

 

[Lavey29]

Maybe the reefmat is working so effectively that it is removing some micro organisms that used to consume phosphate in your tank?

 

[ReefGeezer]

You have a lot of organisms that are doing well at your current phosphate level. Personally, I'd not use NoPox or any other carbon dosing process in such a mature tank. While it may reduce your phosphate some, it will drive nitrates down faster. The tank could become nitrate limited before the phosphates get anywhere near the desired level. That can affect all sorts of other processes. While you could dose nitrates to allow for the carbon dosing process to work, I think the bacteria it encourages also binds ammonia that your corals would prefer to use.

I would suggest that instead of carbon dosing, since the tank is doing so well in its current state, you should simply reduce the phosphate input where you can, and let the tank find its own level. Nori, pellets, flake food and etc. usually have much higher levels of phosphate per unit of protein. Frozen foods can be much better. AND... if you must do something, adding another nutrient processing pathway like live Phyto dosing or a Cheato fuge might be a better choice.

 

[youcallmenny1]

If the corals are happy then it's probably fine for now. I like to keep my PO4 down with a refugium growing macroalgae. NoPox is a fickle beast that can have some backlash with it's use. I would personally reduce import if possible. As others have mentioned, I'd be careful in your scenario about zero'ing out your NO3, whatever path you choose.

On a side note, your tank looks beautiful!

 

[Randy Holmes-Farley]

When I first started carbon dosing it seemed to drop my P04 fairly quickly and N03 slowly but now this...

That was not likely from the NOPOX. As folks note, the effect of carbon dosing on phosphate is small.

 

[Dburr1014]

You have a lot of organisms that are doing well at your current phosphate level. Personally, I'd not use NoPox or any other carbon dosing process in such a mature tank. While it may reduce your phosphate some, it will drive nitrates down faster. The tank could become nitrate limited before the phosphates get anywhere near the desired level. That can affect all sorts of other processes. While you could dose nitrates to allow for the carbon dosing process to work, I think the bacteria it encourages also binds ammonia that your corals would prefer to use.

I would suggest that instead of carbon dosing, since the tank is doing so well in its current state, you should simply reduce the phosphate input where you can, and let the tank find its own level. Nori, pellets, flake food and etc. usually have much higher levels of phosphate per unit of protein. Frozen foods can be much better. AND... if you must do something, adding another nutrient processing pathway like live Phyto dosing or a Cheato fuge might be a better choice.

+1
I was in the same place. Tried vinagar dosing and the cyano was all over the sump. Just getting back to normal now. My tank looks great so I'm stopping to chase a number that probably doesn't mean a thing.

 

[ReefGeezer]

+1
I was in the same place. Tried vinagar dosing and the cyano was all over the sump. Just getting back to normal now. My tank looks great so I'm stopping to chase a number that probably doesn't mean a thing.

The number can mean something. At a minimum, higher levels cause slower calcification so slower growth of some corals and even Coralline. BUT... The effects of trying to lower the number artificially is quite possibly worse. As the OP's tank looks mature and is obviously populated by corals that are not affected by the level, I think it is wise to keep it where it is. I would not always say the number doesn't matter though. I'd also give a big +1 for those who encourage stability. That should be like Reefer's Rule #2: " Change is bad even when it is for the better".

 

[Dburr1014]

The number can mean something. At a minimum, higher levels cause slower calcification so slower growth of some corals and even Coralline. BUT... The effects of trying to lower the number artificially is quite possibly worse. As the OP's tank looks mature and is obviously populated by corals that are not affected by the level, I think it is wise to keep it where it is. I would not always say the number doesn't matter though. I'd also give a big +1 for those who encourage stability. That should be like Reefer's Rule #2: " Change is bad even when it is for the better".

I should have clarified,
Doesn't mean a thing in my tank.
I'm at 0.1 and trying to get it down, bad move on my part.

 

[ReefGeezer]

I should have clarified,
Doesn't mean a thing in my tank.
I'm at 0.1 and trying to get it down, bad move on my part.

Sorry. I didn't mean to sound critical. Mine runs about .06. So a few hundredths above optimal but I'm not doing anything special to control it. I just don't want those that have newer tanks and/or less understanding of the subject to think that the higher phosphate levels are desirable.