so if we remove water to do water changes, is it possible to put that water we changed into a bucket with cheato in it ? outside with the suns growth ? to remove nitrates and phosphates , and then reuse the water for our dt tank
But that's what a refugium does. If you took out the water and put chaeto in it you still have to put that same water back in. Just add a refugium ( water changes still recommended though). Ive been hearing of something called the triton method and I don't know how it works but it seems to be a way to NOT have to do water changes but it I think you still have to invest in trace elements etc. So you still have to spend some cash. Ive heard some guys on here never do water changes. Look around for those.
I can tell OP that NSW would be better than no water changes, and removal and renewal of old salt water to reuse isn't feesiable. I've seen and know of tanks where they have never done a water change just top off, skimmerless and over fed, no reactors and full of fish and softies and tanks seem to do just fine. What OP needs to do is find the right balance of his setup through time, by trial and error.
The Triton lab/company is a lab that checks you water parameters and trace elements with lab grade accuracy. Yes. The triton Method is a way that increases the size of your refugium and acts as your primary method of nutrient export and eliminates water changes. So yea you still have to invest in trace elements so as I said and agree with you, you still have to spend the money but at least it's less work.