First off, it's always better to thaw and rinse well, any frozen food you feed them. Also, don't overfeed, which I suspect a cube is for the stock you have.
I hope that by "freshwater" you mean fresh salt water as they don't live long in fresh water.
As for enrichment of the brine with crushed spirulina, it will work a lot better if you micronize the particles by putting them in a blender with some water and blending them for at least 2 minutes. You can store what you don't need in the refrigerator. Add just enough to lightly colour the enrichment water and if it clears, just add a touch more.
Food particles must be appropriately sized for the size of the brine or they won't take them in. (for adults, 50 microns or less)
. I tried everything I could. Over the course of the last two days I attempted to feed him cleaned and rinsed hikari mysis, and live adult brine shrimp that were gutloaded with spirulina. I cleaned the tank thoroughly and did a 5g water change (I do a 5-7g water change twice a week with substrate vacuum.) I spoke to the breeder I bought him from and it was suggested that I try a low dose of formulin because they treat their horses once a month. I tried that with no adverse effects but no positive either. He still just wouldn't eat and was much less active. I noticed his breathing was much faster at the end. This morning he was dead at the bottom of the tank, in my fake grass bed so I pulled him out and froze him. The female is still doing well, she is eating and even "hunting" the live brine. So now I have to take care of her and get her a tank mate again... To bad it's Saturday though, I can't order another one until monday.
) he felt like I did what I could and is sending me another male for free. As for the girly that's still left, she's vibrant. Truth is she isn't acting too upset about the male. Eating habits are good and she's still hunting.
