Nutrient Drop

RockyTopReefing · Mar 18, 2026

First post! I bought my tank used as a running no livestock tank in November.
Well, I got some hammers, poci, monti caps, lepto, RBTA. For the first few months I was stable around 20 nitrate, 0.2 phosphate. I had my skimmer running 24/7, a month ago it was down to 0.08, nitrate was 17 and I was happy. Well 2 weeks ago I added a third XR15, and that day saw 0.02. I light shocked my tank going from 80 par average to 200. That lasted a few days.

My main question is; will adding 2-3 new smaller fish actually help? I have a clown, royal gramma, fire fish & wrasse, feeding half a cube of frozen twice a day and it’s barely holding my nutrients where they are, but my tank is ticked. Any sort of person who would be willing to be my mentor, I’d even pay. I’ve talked to some local reefers, but I feel like I bother them with questions.

Tahoe61 · Mar 18, 2026

Hi and Welcome.

How big is the system?
What were the very last values for nitrates and phosphates?
You can certainly feed more, and if you're using 3 LED fixtures the system certainly sounds like it's big enough for more fish.

RockyTopReefing · Mar 18, 2026

Tahoe61 said:
Hi and Welcome.

How big is the system?
What were the very last values for nitrates and phosphates?
You can certainly feed more, and if you're using 3 LED fixtures the system certainly sounds like it's big enough for more fish.

It’s a Waterbox 65.4 AIO. My latest test which was 3/15 was 13.2 Nitrate, 0.03 Phosphate. It’s not huge but is a 4 foot tank. My par went from 80-200, and I’m thinking it caused bacteria to suck down nutrients like crazy. I have 3 XR15 G6 Pro’s on the tank, managed to have it sit at 100 par now, and over 30 days will ramp closer to 150-170 at peak spots like where my hammers are.

Tahoe61 · Mar 18, 2026

Those numbers aren't horrible. How do the corals look?

You could definitely add more fish and increase feedings. If that doesn't move up the values you could proceed with dosing nitrates and phosphates and or dosing Ammonium Bicarbonate.

Consider creating a tank thread to encourage other members to offer input.