Topping the Res.. Or Not?

Using a 55gal res. with somewhat of a lucas formula.

Question is, how essential is topping the reservoir every couple of days?? Regardless of it being with or without nutes, is topping completely necessary or could one just wait and do a complete res change every week or two, with no topping/adjustments to the res.

I am a lazy git, i often let mine drain down to an inch of water before i fill them up again and they don't seem to mind too much, that is to say i see no averse effects from doing so.

I've never used lucas formula and have no idea how it works but..

I've run several different systems without topping off the res. As long as
the PH and PPM are in check they should be fine. I would still recommend
changing out your nutes weekly/biweekly to help avoid buildups and lockouts.

Personally I prefer to only top off when they're drinking up too many of the
nutes and not enough water to help balance things out. But otherwise I try
to keep it dialed in to exactly what level my girls are drinking.

Kinda of how ive been doing things.... just was worried of bad effects. thanks.

There shouldn't be any negative effects if you're still changing/flushing your
reservoir at least biweekly. I've seen and read about people never changing
but that just makes me nervous as I'm not that confident.

I never add water until i have to because the pumps need more water to run. The plants dont care either way. I do add more nutrients as i add water though. but only in what im adding so that im not just adding plain water into it and lowering ppm. If i add 5 gals i adjust that waster to same nutrient level. Im proably just wasting nutrients, but who knows. its a 25 gal res and after 5th day they drink over 5 gals so the table wont fill all the way. I just bought a 40 gal res that im gong to switch to so i dont have to do all that work.