Analysis of Trace Elements in Different Brands?

[teddscau]

Hey guys. I've been working out the kinks with raising larval invertebrates. Anyways, I read an old study on the survivability of urchin larvae in various brands of salt (Instant Ocean, Coralife, etc.), and there's a huge difference in survival based on what salt mix is used due to the different levels of trace elements found in each brand. However, it was a really old paper, and I was wondering if anyone had any links to more recent studies on survivability or analyses of the chemical composition of various salts. Thanks guys .

 

[mcgyvr]

Good luck...sounds interesting...

 

[teddscau]

My eyes are bleeding from reading all the confusing numbers -_-. I'm trying to read the analyses from various studies, but they all use different units of concentration. It's so confusing. I think I'll just have to convert everything in a separate file :x.

 

[bertoni]

There are a number of issues. First of all, the ingredients for salt mixes varies with the price of various commodities from various vendors. Secondly, even the target parameters change from time to time. I'd probably try a few mixes and work from there, if possible. If you got a baseline for survival, you could test subsequent batches.

 

[teddscau]

Wow. That...that sounds like a lot of effort on my part. I guess I could buy a bunch of different mixes, buy some more tuxedo urchins, then induce spawning in them and see which salts have the lowest larval mortality rate. I don't have a lot of space, so I might only be able to have three or four separate groups of larvae to test each salt.

It's definitely a pain trying to raise larvae, but it's definitely a worthwhile endeavour. It's just so difficult because there aren't a whole lot of scientific papers or guidelines on how to raise them. Right now I'm having issues with the infants, after six days or so, struggling to swim. They'll lay there on the bottom of their container, too exhausted to swim. I think I might just quit trying to use a bubbler for aeration.

 

[Vinny Kreyling]

Martin Moe has been trying with Long Spined Urchins for a few years now.
PM me.

 

[teddscau]

Well, I feel a HUGE factor in the failure of marine invertebrates larvae to thrive is due to the deadly amounts of silver found in the salts available on the market.

https://www.amnh.org/learn-teach/cu...-of-silver-nanoparticles-on-aquatic-organisms

According to that guy, 0.027 ppm in vitro was enough to kill freshwater invertebrates. From all the different charts and tables I've looked at, the trace elements are way too high in pretty much every brand of salt. When raising marine larvae, it seems as though you should only use 2/3 reef salt, then finish raising the salinity by adding pure sodium chloride. I mean, adult invertebrates can handle less than ideal levels of trace elements, but larvae are extremely sensitive.

 

[bertoni]

You could try making your own salt mix. I don't know how consistent the ingredients would be, but they might be more consistent than the commercial supply. It'd take some good measuring equipment, and it would be pricier. I can dig up a recipe if you're interested.

You also could consider adding a PolyFilter to the prep stage, followed by some CupraSorb. The two might remove enough to be useful. The PolyFilter will leach some copper, possibly, so I'd consider the CupraSorb step, at least.

 

[Vinny Kreyling]

teddscau,
Heard from Martin --
He says Diadema are the most sensitive & Nickel is Lethal @ 15 PPB.
Environmentally acceptable is 75 PPB.
Nickle is used in making Stainless Steel.
He had to use rainwater & Tropic Marin salt.
He also hopes to have the manual for raising them done soon.
Hope this helps.