high nitrate and high alkalinity

Question
I have a 90 gallon tank that is fairly new. I cycled it about 8 weeks before adding any live stock. I have a little over 100 pound of live rock about a 3 inch sand bed.
I also have a refugium with refugium mud, live sand and live rock. I do not know the brand or type of skimmer because it is written on the bottom and it is in my refugium under my tank. I have two pair of false perculia clowns, 1 sail fin tang, 2 cardinals, 2 fire fish, and a coral beauty. A far as filtration I was trying to do everything naturally so I have no Canister filter. My nitrates are out of site and my alkalinity is very high. I do water changes once a week, about 25 gallons.  Also I have some soft corals that seem to be doing fish. Also my fish seem to be healthy. Just am worried a little about the nitrate and such. Any help will be deeply appreciated.

Answer
hi, try taking a water sample to your local fish shop for testing, could be your nitrAte test kit thats bad.

could be also worth getting your RO water from somewhere else or change the filter membrane if you make your own.

what algaes do you have in your refugium? these should help with the high nitrAtes