My tank is a little over a year old and I have noticed nitrates are starting to rise on the API kit its hard to tell but its either 5.0 or 10ppm they look like the same color. Also phosphates I can't get below .46ppm on the Hanna checker. I have tried the Kent phosphate sponge which pulled it down from almost 1.0ppm. I use rodi
water and do 2 week water changes on a 180g tank of 30g. Could it be the sponge block that's in the sump just before the return pump it a adhi 45 sump. I am running chaeto in the center of the sump. Any ideas? Should I do vodka dosing? I know after 2 things of the phosphate sponge I see I wasted $40. Also do I need the sponge in the sump or can I take it out and just let the water run straight to the return pump?