Teach me the way of 0 no3

[TimeSlayer]

hi, any tips would be welcome.

My no3 is at 5 ppm it stay around that. I'm trying to get it to close to zero as i can so i can get so sps.

Tank info
150gallon main tank 75 gallon sump tank, with 180 pound of live rock.
1 carbon reactor change once every 2 weeks
filter sock change every time i get up to turn the lights on
1 skimmer a vertex omega 180i
3 hang on the back filter with nothing in it just for flow
1 25wp jebo
with a refugium growing caulerpa the grape one. light for 12 hrs.. remove 70% of it once it grow close to my skimmer
4000 Lifegard Aquatics Quiet One Pro return pump

fishes..... the year are how long i had them for.
1 big clown 2.5inches 3 yr
1 small clown 2inches 3 yr
1 sail fin tang 4 inches 3yr
1 hippon tang 5 inches 3 yr
1 Foxface Lo 6inches 3 yr really like this fish he is really nice
1 scooter benny 3yr
1 Cardinalfish full grow 3 yr
1 Flame Angelfish 4 inch 3 yr
1 Longnose Hawkfish 2yr
1 its a Blue Angelfish or Queen Angelfish cant really let the juvenile apart...:hmm2: only pay $20 for it. its 3.5inches 2yrs
i feed them 2 freezen food table once a day

i do 35 gallon water change once a week and vacuum the sand with it
i dont have algae problems just some green that would grow on the glass i need to clean off in the water change

i just started using a ro/di water in nov.

I dont really know what i can do more to bring me no3 down more. i was thinking of bumping my water changes up to 50gallon instead of 35 gallons.

I do have a new thing of PhosGuard. i dont know if i should use it. I brought it a yr ago and never use it. I just dont want to crash my refuguim. Would the PhosGuard help the refugium target no3 more? if the PhosGuard taking care of the phosphate?

im just try to get my no3 at 0 bc i hear form alot of ppl say you need it 0 for sps. And i would like to get some sps corals.

[ReefPharmer]

I have sps and let me tell you, you don't want 0. 5 NO3 is not only acceptable but preferable. Many people dose NO3 to keep it from being 0. What you want is lowered phosphates (not 0 but maybe 0.02). Phosphate is what you need to control unless your nitrates are waaaay up which is 20+ in which case you need to improve nutrient export, decrease feeding or both.

[heathlindner25]

3-5 ppm is what I keep for acros.

[Bogue Chitto]

You probably are getting too many nutrients from over feeding. Try feeding less for a while and see if that helps. Fish always act hungry, it's their nature, but you have to feed them sparingly.

[TimeSlayer]

that cool to hear my no3 is ok ty