consider getting more LR. about 1 lb per gallon of water. this will help with ur biological filtration and also help reduce ur nitrate. i do agree with the use of RO water, it is much much more stable. keep up on ur partial water changes, and this should help your nitrates come down. also if u dont have a protein skimmer, try adding one. this will help draw out all of your waste material, such as fecal matter and urine. make sure there is no ammonia in ur tank, and that it is cycle. other wise the nitrogen cycle will keep adding more and more nitrate. after your parameters are where u want them, go about slowly adding more fish if u wanted too. i also agree with the refugium. this will allow you to grow algae in there, which will absorb a lot of nitrates in the process, leaving you with lower levels as they enter your tank. good luck
