Low po4 high no3

[Randy Holmes-Farley Verified Community Expert]

FWIW, I'm not a big fan of the idea that one can control the ratio of N to P consumed p by trying to get different types of bacteria to grow in the tank.

 

[Herpdederp]

FWIW, I'm not a big fan of the idea that one can control the ratio of N to P consumed p by trying to get different types of bacteria to grow in the tank.

Why not? Does bacteria naturally repopulate with a stable chemistry? Ideally I want to get to a point where I can rely on just water changes to keep things balanced. Most reefer's I've met in person all dose bacteria, but not all within the same amount of time, some once a week, some once a month. Then on the internet people document no water changes and only water top off and everything is in balance.

 

[Randy Holmes-Farley Verified Community Expert]

Why not? Does bacteria naturally repopulate with a stable chemistry? Ideally I want to get to a point where I can rely on just water changes to keep things balanced. Most reefer's I've met in person all dose bacteria, but not all within the same amount of time, some once a week, some once a month. Then on the internet people document no water changes and only water top off and everything is in balance.

Maybe you are misunderstanding my point.

Most bacteria make similar biomolecules that will have both overall N and P amounts in them that do not greatly diverge from one another.

Thus, I do not think you can readily develop a set of bacteria that uses far more P or far more N than other bacteria.

Hence my point that I do not think it is worthwhile to try to alter the relative consumption of N and P simply by dosing a particular type of bacteria.

The primary divergence from this involves denitrifying bacteria. They have similar N and P in them as other bacteria, but they carry out the denitrifying process to gain energy, and that chemically changes nitrate to N2. But to keep more of these growing, I expect that one needs to dose specific food for them (organic carbon dosing) and/or provide appropriate media for them to live in.
What I don’t think is that just adding more of then will have an effect similar in magnitude to just organic carbon dosing.

I also do not know of a good way to drive bacteria that consume far more P than usual. Some bacteria store phosphate as polyphosphate, but getting them to grow that way long term in a reef seems challenging to me.

 

[Jaymang]

Hey Jay, I reckon I managed to find what I was missing. Since around 3-4 months ago I swapped bacteria from Bactive8 NPX to Nitribiotic. I am guessing Nitribiotic dosing by itself is not enough to sustain healthy bacteria for the po4 to bond and stay to the correct ratio to no3. If you run out of ideas try using a different brand of bacteria. I'll report back in a week or so with my readings, but as of today the no3 in both my tanks dropped by 2ppm and po4 stayed above 0.08. Can't wait to get back to regular feeding! Oh I also found that when I didn't have the correct bacteria dosing any kind of carbon, NP balance product just sucked up all the po4. I currently use NP bacto balance from Tropic Marine.

That's good news! Sad to say, I haven't been dosing bacteria in a form of carbon dosing like you. Still unsure what is taking up the po4. I use Microbelift Special Blend as a denitrifying bac source. (or could this be the case; the same as you) However, I haven't been adding special blend in for a while now. po4 still gets taken up rapidly.

 

[Herpdederp]

Hmmm the chemistry is improved but not ideal. I'm using sponge filter pad, would that be the reason for sucking up all the po4? I mean aside from the LR and substrate I can't think of anything else that would strip absorb po4 this quickly. And since I wash the pads every 1 - 2 weeks I could be rinsing all the absorbed po4 out for the sponge to start soaking up po4 from scratch. Or am I just completely wrong? haha. Looked online but couldn't find any discussions between po4 consumption and sponge filters.

Big tank was doing well but no idea why it shot back up again. I've been mostly feeding dried pellets in the big tank. Small tank mainly pellets and brine once every week, if I do any more the no3 will sky rocket. Apparently overfeeding pellets in my case will just bring up the no3 very quickly without disturbing the po4 at all.

 

[Jaymang]

Hmmm the chemistry is improved but not ideal. I'm using sponge filter pad, would that be the reason for sucking up all the po4? I mean aside from the LR and substrate I can't think of anything else that would strip absorb po4 this quickly. And since I wash the pads every 1 - 2 weeks I could be rinsing all the absorbed po4 out for the sponge to start soaking up po4 from scratch. Or am I just completely wrong? haha. Looked online but couldn't find any discussions between po4 consumption and sponge filters.

Big tank was doing well but no idea why it shot back up again. I've been mostly feeding dried pellets in the big tank. Small tank mainly pellets and brine once every week, if I do any more the no3 will sky rocket. Apparently overfeeding pellets in my case will just bring up the no3 very quickly without disturbing the po4 at all.

I don't think feeding is good to raise specifically po4. As you said, it'll increase no3 as well. I think the best is to dose phosphates. I'm currently 1.5weeks into my dosing and I still read 0 po4. I'm a bit worried to overdose if I get it wrong My corals don't look too bad and so I'll probably just leave it as it is. my no3 is at 5ppm on salifert. 27ppm on hanna. po4 0