Zero nitrates, high phosphates

[avocadoman]

Problem: my nitrates have slowly fallen to zero (7.8 on 4/21 to 0.0 on 5/11 on the Hanna checker and confirmed with API test) while phosphates have crept from 0.07 to 0.23 over the same timeframe.

50 gallon tank plus sump, about 4 months old now. I have three fish (fire fish, diamond goby, carpenter's wrasse) along with a cleaner shrimp and a good complement of snails and hermits. Two corals (hammer frag that seems to be growing well and a favites frag). I've been running a chaeto refugium for almost two months. When the nitrates hit 0 about 4 days ago, I removed all but a tiny piece of the chaeto. Nitrates are still 0 today and phosphate has increased a little.

I work long hours so I have an Eheim feeder giving TDO Chroma Boost twice a day. I feed frozen mysis and brine shrimp whenever I'm home. I use a filter sock and a Deltec 400i skimmer.

I'm dosing All For Reef to maintain alk and Ca levels.

I've been fighting diatoms for a while but they seem to be lessening a bit. Scared of getting dinos or cyano or something with no nutrients around. Or starving the corals.

Current parameters:

Salinity: 34 PSU
KH: 8.4
Ca: 440
Nitrate: 0
Mg: 1440
Ammonia: 0
Nitrite: 0
pH: 7.9 - 8.1 on Seneye

Please help!

 

[TX_REEF]

have you considered dosing neonitro to get a stable nitrate level?

Amazon.com

 

[avocadoman]

have you considered dosing neonitro to get a stable nitrate level?

Amazon.com

I'm considering it. I'm wondering if there's something else I can do, or something I'm doing wrong, before resorting to adding more products to the water. Like where is all my nitrate even going?

 

[TX_REEF]

do you run a skimmer? If so, you could try reducing it's operating time. I had zero N and P for months and shutting off the skimmer did the trick for me, my nutrient export is now all handled by an algae turf scrubber.

 

[Lavey29]

I'm considering it. I'm wondering if there's something else I can do, or something I'm doing wrong, before resorting to adding more products to the water. Like where is all my nitrate even going?

Pellet food raises phosphate in the tank. 0 nitrates means your corals are starving and also can't process phosphate in the tank. Feed more frozen to raise nitrates and dose neonitro. I had to double dose neophos and neonitro for multiple months before I got measurable numbers when my tank was new.

 

[avocadoman]

Pellet food raises phosphate in the tank. 0 nitrates means your corals are starving and also can't process phosphate in the tank. Feed more frozen to raise nitrates and dose neonitro. I had to double dose neophos and neonitro for multiple months before I got measurable numbers when my tank was new.

What is consuming all the nitrate? Will I just have to dose nitrogen forever, or will something change as the tank matures?

Maybe I'll turn the skimmer off for a couple of days and see what happens.

 

[Lavey29]

What is consuming all the nitrate? Will I just have to dose nitrogen forever, or will something change as the tank matures?

Maybe I'll turn the skimmer off for a couple of days and see what happens.

Its just typical unstable 4 month parameters. I feed 12 fish 3x per day with frozen to maintain nitrates in a heavily stocked mixed reef.

Your skimmer provides 02 to your tank not just export

 

[Randy Holmes-Farley]

I’d dose food grade sodium or calcium nitrate, or ammonium chloride or bicarbonate. Less expensive than hobby products and have a purity assurance they lack.

Trying to figure out and eliminate a sink for nitrate is likely not going to lead to a solution.