Now PO4 is undetectable


Active Member
Reaction score
18 months ago I had 2 tanks (60g & 29 Biocube) with 75ppm+ Nitrates and PO4 usually higher than .7

Yesterday during testing on our 120g (replaced the 60) NO3 is below 3 (Nyos) and PO4 is undetectable (Hannah low tester). I'm fairly confident the test kits are fine as all reagents are well within expiration plus they are also used on our 30g (NO3 @ 5-10, PO4 at .71).

I'm happy with how I'm stocked and since my quarantine / holding tank is now home to a picked on goby I'd rather not add more fish.
  • 3" Lightning Maroon Clown
  • 3" Kole Tang
  • 3" Yellow Choris Wrasse
  • 2 Purple Fire Fish
  • 2" File Fish
  • 2" Fox Face
  • 3" Speckled Hawkfish
  • Sand sifting star
  • Tiger Tail cucumber
  • handful of snails / small blue leg hermits
  • Pistol Shrimp
Tank gets fed once per day with a half dollar size chunk of frozen plus a half sheet of Nori roughly 4 times per week. Tank has about a 2" sand bed, probably 125lbs of rock, in tank flow varies anywhere from 1500 GPH up to 6000 GPH (dual XF230 Gyres that run between 40% - 100% plus 2 Tunze 6095 that run between 50% - 100%). I have no idea how much flow my return pump is actually providing.

I run a Life Reef SVS 24 protein skimmer with a CO2 scrubber and skim very dry. 5 days after cleaning out skimmer cup / locker I have about half inch of skimmate in the cup.

I did dose Nitrate a few weeks ago because my NO3 was undetectable and PO4 was .07. I got the Nitrates up to about 10 but they are slowly falling since I've stopped that dosing.

Yesterday I altered my skimmer schedule to shut it down for 7 hours during the day with the hope that may help get my nutrients a little higher. Based on how little skimmate I actually collect right now I'm guessing it's not going to make a difference.