Phosphates and Nitrates sitting at 0

robotrash · Oct 8, 2023

Been reading around and I see a lot of threads about them being out of sync (one high, one low) but trying to work out how to address my zero nitrates and zero phosphates together.

My tank (IM Nuvo 20G) is coming up on 2 months old, mixed reef long-term but currently softies, some euphyillia, and a couple of Favia frags. Only fish is a pair of very tiny black storm clowns (<2"). I mention this as I don't need to be feeding them a bunch of food (in volume). I do have a good size CUC and a cleaner shrimp as well.

Everything is looking good and healthy, I am definitely in the throws of the ugly stage at the moment with any exposed rock sections covered in algae as expected.

I feed the coral almost daily, typically targeting larger mouths with the brine or mysis I'm feeding that day. I feed reef roids 2-3 times a week for the smaller mouths. Feeding response seems good across the board.

I do not dose anything currently. Filtration in the AIO is 4 filter pad layers followed by live rock rubble (true live, not seeded dry). The other chamber is filter pad -> chemipure blue -> marinepure balls/gem combo.

Tank has about 20lb overall of rock, about 12lb of it was fully live at the start of the tank, the other 8 is the liferock dry rock.

Is zero for both of these things a danger currently or something not to worry about this early? I'm avoiding chasing numbers currently (I'm slightly low on the big 3 at the moment but stable) and wondering if maybe I should just up my feedings? Maybe reduce WCs (currently 10% weekly)?

My most recent test results:

Salinity: 1.025 (Electronic test and refrac)
Ammonia: 0 (Red Sea)
Nitrate: 0 (Red Sea)
PH: 8.3-8.7 (electronic test and strip)
Alk: 6 dkh (tested twice, Red Sea)
Calc: 355 (Red Sea)
Temp: 78
Phos: 0.015 (Red Sea)

Reefahholic · Oct 8, 2023

Stop all water changes first. Remove the chemical filtration first. Then the mechanical filtration right after that, and see what that does. Feed more in the process. Reef Roids is loaded with phosphate so it’s a little surprising you’re sitting at zero. Personally, I’d just dose it up, because the quicker you get it up the better the tank will do. Buy some NeoPhos and dose .02 ppm every day (every 24 hrs) until you get up to .06-.08 ppm PO4 and hold it there and see how it dose for a while. If the Biomedia is still sucking down your NO3, I’d remove that later on too.

When PO4 bottoms out it, algae will blow up. It may seem counterintuitive, but you need to get the PO4 up regardless of how much algae you’re looking at right now. When PO4 starts to increase, you’ll notice the algae will not thrive as well, and will start dying back. Keep in mind that your in the early ugly phase and some algae will be normal. It usually does start this bad until the 3rd or 4th month. So I suspect you were low or at zero for a while? Also, adding 1 ppm daily of NO3 would help. For every .01 ppm PO4, add 1 ppm NO3 every day (every 24 hrs).

100:1 ratio will be .06 and 6

Good luck!