Here is Aquarium Systems response. I guess the ICP tests we are all paying for are in accurate then!
Thanks for the information about the multiple testing of the salt, RO water and aquarium water.
They are different topics of discussion in the following thread of emails.
First and main one is potential high Zinc level in Reef Crystals. To be totally open, we are manufacturing Reef Crystals with batches of 600kg, that means we make about 30 buckets with exactly the same batch, so we would have had same issues with other hobbyists and professionals. In addition to create Reef Crystals we are using chemical raw materials obtain from industrial batches that are substantially larger, with consistent chemical profiles throughout days or weeks of production (for example the Sodium Chloride regular batch is over 100T, same for Magnesium). Knowing this, the absence of numerous similar issues implies the absence of contamination.
The second topic, which is more difficult to realize, is about testing seawater. When we use a simultaneous, multi-element analysis, it cannot be precise. These types of analysis have usually a wide range of accuracy, because some elements interfere with each other in the readout. To have a really accurate quantification of zinc, for example, the element should be analysed separately with precise calibration of the standards. To corroborate my example, when we externalize our tests, we use 1 of the 4 laboratories in France that is qualified to test seawater. I looked at the last analysis and just for Zinc the cost is over 60€ without the bottling and sampling. When we do a complete analysis it costs us over 1200€ externally, and needs about 1 month to have feedbacks. Then we use these to benchmark our in-house analysis. Knowing this I think it is reasonable to also question the veracity of broad spectre analysis which costs 50€ for 40 parameters.
Last but not least, the best indicator of wellbeing of an aquarium is visual. We usually forget that an aquarium is as much chemical as biology... the aquarium is going to have a balance and a thriving aquarium is the best sign of good health.
I hope this help,