Hello, Any recommended test kits I can get to test for magnesium, phosphate, and all the minerals that plants thrive on? I have the API master kit. My temple plants are getting holes in the leaves. It will start at the tips and work itself to the whole leave and the leaf will disolve in the water. It starts with old leaves first. I've read it could be magnesium, and other things. I have black diamond sand. Tank has been doing great for 3 months, and now the plants don't look so great. I added more osmocote root tabs last week. Dosed with Flourish in the beginning - no improvement, then did API Leaf Zone, still no improvement. Also, now my Water Sprite is staring to brown at the stems and die off. Java Fern was browning at the base, but now it is getting better there, but the leaves are now starting to get holes, too.