Ebb & Flow questions????

I'm using a 50gal res..

1- I plan to change the res water every 7-10 days.. is this okay?

2- So I add nutes after I change the res water but do I add any during the week or just keep topping up with plain ph'd water and add nutes only once every 7-10 days when I change the res water?

I'm in no way an expert on the subject but my understanding is that you can change the solution every 14 days and normally just top up with water and at day 7-8 try to bring it back to where you start. If you try to keep it there I think you'll be biting off a big one.

What do you mean if i try to keep it there? You mean trying to keep it there constantly everyday?