Coral growth issues..

[iceman86]

I wouldnt trust that api kit. I also have one kicking around and my tank also measures .25 but if I use any other trusted kit, my readings are undetectable and I dont use any gfo either.
For the longest time I just kept changing my gfo cuz it always gave me a false reading until I bought a good test kit.

About coraline algae, not having any doesnt mean much. Ive never had coraline algae grow in my tank and growth has always been awsome. Theres a few amazing tanks online who never get any coraline algae either.

Wait till your test kits come in and go from there.