i use the serra test kit which is not that great imo and so i took a water sample up to my lfs today and the guy wanted to prove a point to me that it was indeed a bad test kit i was reading on serra 20-40 nitrates and all the other readings mag calc etc were all way lower than they should have been, so long story short he tested with two different test kits on my water sample and they both read 2 nitrate ph 8 mag 1500 calcium 550 phosphate 0.03. I took the water sample there to try and see if i should set up a refugium for my nano tank and he said absolutely not and that my corals are not looking great because the possibly have mag burn and that 2 nitrates is to low for a softie tank and that they are not getting enough nutrients (i keep zoas leathers and xenia/clove in this tank) he said i shouldnt do a water change because i have been doing 20% every week he said that was to much and that i need to get the nutrients up in my system to around 10-15 nitrates and then do a 20% and that will lower the mag and calcium down. he recommended 400 calcium and 1200 mag for softies. question is does this all sound correct or will the high mag and calcium do more damage than the low nutrients will? how should i approach this with what he recommended or another way? the way he recommended to raise the nutrients was to feed frozen food in small servings several times a day to make the fish produce more waste but not to feed so much they arnt eating it and the food is rotting away.