So, those of you who were at the last meeting know that my phosphates were pretty high in my tank (0.4 something I believe, with Scott's photometer). I've been doing 5 gal H2O changes almost every day, and running Kent's Phosphate Sponge (changing it out every day). I also got rid of my sun coral in an effort to not have to feed my tank as much.
I tested my tank today with a Salifert kit numerous times, and it comes up 0 every time. The water in the vial is clear as can be. RO water is also testing 0 with that kit. I tested both my tank and RO water with my Red Sea kit, and they're both coming up 0.1ppm. I've had the Red Sea kit for awhile, but I can't seem to find an expiration date on it.
I'm just wondering if there's any sort of test you can do to see if you're PO4 kit is very accurate. You know like how you add baking soda to water, and you can test your alk kit against that. I tried testing my tap water too, just for the heck of it, and I got the same readings. 0 on Salifert and 0.1 with Red Sea.
Anyways, I know test kits aren't always accurate because the phosphate could be used up as fast as it produced and all of that. I was atleast hoping it could show me if my PO4 levels were lowering or not. I'd really like to believe the Salifert kit since I think they're a pretty reputable company, and I want my phosphates to be at 0 like Salifert says they are, sooo.... Does anyone have any experience with kits and get accurate results, or any suggestions?