Let me hear your thoughts on black sand.

[fryman]

Lithium and bromide aren’t generally much concern and I would not attribute them to black sand.

How long has the sand been there? I would expect the release of potentially problem metals declines over time.

I’d also say that not all black sands are necessarily the same. A natural ocean black sand may be far less of a concern than something made from ground up black rocks, because the freely releasable metals are gone from the ocean sand.

I've had the sand wet for about 5 years. I didn't really add corals until more recently, kind if a long delayed start for this tank.

I did my first ICP test on this display ~4 yrs ago and it looked very different. At the very beginning it had high Strontium (11.8 mg/l), Zinc (11 mcg/l), and Aluminum (76 mcg/l). I think the aluminum was from marinepure which I removed about a year ago. Maybe over time the strontium & zinc all leached out?

Now that zinc is low, is this something that's worth dosing? Last ICP measured 0.22 mcg/l for zinc

Thanks!

 

[Tangy Reefer]

I've had a 120gal mixed reef setup with 60lb of carib-sea hawaiian "Arag-Alive" black sand. I admit I don't have any "fancy" sps, just some bird's nest, bubblegum digi and purple stylo which grow fast.

My last ICP looked pretty good to me (oceamo MS)
slighly low: boron, chromium, and nickel
low: manganese, selenium, vanadium, zinc

slightly high: lithium (382 mcg/l), bromide (101 mg/l)

Everything else was in normal ranges.

I use IO regular, and dose iron daily (this is the first time I measured any iron). I weekly add Manganese, Vanadium, Molybdenum, Flourine, Silica, Nickel, Cobalt, Selenium, and Chromium. I may have to switch manganese and vanadium to daily because they are perpetually low.

I've been adjusting upwards on trace dosing but still haven't quite nailed it. I dunno if low zinc is a concern?

I don't believe the black sand is leaching anything, but if the lithium & bromide are a concern I'd like to know.

Thank you for this insight