High Zinc in ICP Test & Switching to ATI Essentials – Need Advice

CalypZoo Reef

New member
I’ve got a couple of questions that I can’t quite figure out on my own, and I’d love some advice from the community.

1. Elevated Zinc in ICP test
My tank is now about 8 months old and has gone through the usual algae and bacterial phases fairly smoothly. For the last 3 months I’ve been dosing All-For-Reef and my corals were doing well.

However, during my vacation a few weeks ago, I lost 5 healthy, fast-growing SPS frags rather suddenly. When I came back, my parameters looked fairly stable, but I noticed some nitrite showing up in the test. The display itself looked clean, but there was a lot of detritus buildup in the sump.

I decided to run an ICP test, and the only unusual value was Zinc, which came back at about 5x higher than recommended. Everything else looked reasonable (Tin was slightly elevated but only marginal).

Here’s what I’ve done so far:
  • Disassembled and cleaned all powerheads and return pumps
  • Emptied and cleaned the entire sump
  • Checked for any rusting or corroded metal parts – everything still looks new
  • Performed ~70% water change
  • Ran a Triton Detox course to bind heavy metals
  • Currently running Poly-Filter and activated carbon to remove contaminants
The tank looks fresh, but I haven’t found a clear source for the Zinc. My plan is to run another ATI Pro ICP test in a week or two once things have stabilized. Hopefully the Zinc is gone by then, but I’m curious if anyone has other ideas of where to look or what else I can do?

2. Starting ATI Essentials (Pro vs Plus?)
I’ve heard great things about ATI Essentials and I’d like more control over my dosing. I have both the Pro and the Plus versions at home, but I’m not sure which one to use..

My tank (450L / ~120g) doesn’t have that many corals at the moment (see photo), but I do plan to add more over the coming months. Eventually I’d like to keep a nice mixed reef.
  • Should I go with Pro , or is Plus better?
  • What’s the exact difference between Pro and Plus?
  • I also have the ATI Nutrition C, N & P bottles. Do these only go with Pro, or with Plus as well? And can they be diluted with RO water?
  • For dosing, the ATI calculator asks for a lot of water parameters. I’m not fully confident I’m entering things correctly, so I’d appreciate if someone could suggest a good starting dosage for my tank. I’ll be testing KH daily and adjusting from there.
Current parameters:
  • Temp: 24.6 °C
  • Salinity: 1.025
  • pH: 8.0
  • KH: 6.4 dKH (a bit low since I stopped AFR 2 weeks ago, came down from 8)
  • PO4: 0.12 ppm
  • NO3: 3.7 ppm
  • NO2: 13 ppm
  • Ca: 440 ppm
  • Mg: 1410 ppm

My Tank:
WhatsApp Image 2025-08-19 at 18.33.28.jpeg


My cleaned sump:
WhatsApp Image 2025-08-25 at 15.59.21.jpeg





Any thoughts on the Zinc situation or tips for getting started with ATI Essentials would be greatly appreciated.

Thanks in advance!
 
Zinc most commonly comes from a piece of galvanized steel like a bolt or screw dropped in the tank. Perhaps a hose clamp?
Usually you will see elevated levels of tin, iron and perhaps molybdenum as well.
Some fish foods contain a lot of zinc.

Never used the ATI product sorry.
Go easy adding stuff you cant test for and can only see with an ICP unless you plan to do them regularly.
 
Back
Top