nitrates at 0, water change?

i have been doing weekly water changes of %25 on my biocube 14 for the last year and a half, but now my nitrates are at 0 after doing some tests the other day. I think my refugium is finally catching up by leaching the nitrates produced by my fish. So is a water change necessary? I am gonna start dosing the tank in a couple days so, im thinking that i want to see how much my levels of cal, mag, alk dropped in a weeks time, so i can figure out a dosing schedule. Does anyone have any advice for me? It would be great if i could start dosing and stop water changing so much?

 

I would suggest continuing water changes , even when you are dosing
as its likely that water changes do refresh minor and trace elements that we do not test for

but IME you do not need to do 25% weekly

I currently do 5% each week and must hit 48 weeks in an average year
and I do slightly more the week following any week missed

I would start with 5% but continue monitoring your parameters
if they begin to increase, possibly up the QTY of water change to 10% weekly

but in a well maintained system, 5% has proved adequate for me over a 2 year plus period

Steve