Dosing neonitro phosphate went up?

reefscrub_ · Aug 3, 2023

Hello!

So I’m running into an issue with my reef tank, it’s a 40 gal breeder that’s been up for 4 months.

In June 18 my phosphate was at .02 and nitrate at 4.5. In my book those were great numbers.

Fast forward to July 31 I was at .9 phosphate and 0 nitrate. Ridiculous numbers.

So I decided to dose Brightwell aquatics neonitro to 2ppm nitrate.

August 1 I was at .78 phosphate and 1.7 nitrate. Still terrible but I saw improvement which was good.

Today I tested again and I’m back at .9 phosphate and .8 nitrate.

Testing using hanna phosphate ulr, and hanna nitrate hr.

I was hoping the phosphate would keep declining. Now I’m at a loss. I know that nitrate is still being taken up which is a good thing. But I don’t know why phosphate went up again instead of down. Maybe it was the new addition of Benepets reef food I’m trying out? Or perhaps I’m feeding too much pellets? Or maybe I’m Carbon limited?

Either way I bought a bottle of biofuel which is a Carbon source, not going to use it unless both nitrate and phosphate stop dropping. I cut back feeding, only feeding 2 times frozen daily and daily animo acids, nothing else. Going to test again tomorrow morning and check to see if it hopefully drops phosphate on its own now that I cut back feeding.

For info I was feeding 3 times daily mixture of frozen mysis and pe pellets, very tiny tiny amount seeing as I only have a small melanurus wrasse. Daily 5 drops amino acids from Brightwell. Every other day 5 drops fauna marin min s. And recent addition of benepets which I only fed once, which I’m hoping is the issue since it’s the only new change. I also run a proper size skimmer 24/7.

Any input would be greatly greatly appreciated, thank you!

Randy Holmes-Farley · Aug 3, 2023

I think the title does not sum up what happened.

Between June and July, phosphate increased a lot (assuming the values are accurate)

Then you dosed neonitro. You saw a small increase in nitrate and an unexpected (and possibly not real) drop in phosphate.

Then phosphate went back to where it was. Its currently no higher than when you started neonitro.

I see nor reason to think neonitro caused any increase in phosphate, and I would not have expected any significant drop in phosphate from low doses of nitrate over a few days

Ignore the idiotic comments by Brightwell about carbon limitation. EVERY reef tank is carbon limited as is every part of the ocean, unless N and P are in such low supply that corals are dying. You always want a reef tank to be organic carbon limited.

I'd just keep dosing N somehow (I recommend other produicts as cheaper and of known purity) and keep nitrate above 2 ppm.

reefscrub_ · Aug 3, 2023

Thank you! Yeah sorry for the misleading title dosing neonitro DID NOT CAUSE phosphate to increase. You’re probably right it’s still just where I started. I’ll continue to dose neonitro and monitor n and p. I’ll update this post with the findings.

Zeeter · Mar 3, 2024

reefscrub_ said:
Thank you! Yeah sorry for the misleading title dosing neonitro DID NOT CAUSE phosphate to increase. You’re probably right it’s still just where I started. I’ll continue to dose neonitro and monitor n and p. I’ll update this post with the findings.

Where did we wind up with this? My PO4 is at .045 but my nitrates are at 1.01. I'm trying to get the NO3 up to 5 without increasing my PO4.

Randy Holmes-Farley · Mar 3, 2024

Zeeter said:
Where did we wind up with this? My PO4 is at .045 but my nitrates are at 1.01. I'm trying to get the NO3 up to 5 without increasing my PO4.

Dosing ammonia or nitrate is a fine way to go. It will not raise phosphate .