Fertilizer injector + pesticide question

[BrassavolaStars]

Hello all,

I am preparing to do some pre-fall changes to my greenhouse "infrastructure". One of the things I had my eye on is a fertilizer injector like this

https://www.amazon.com/Fertilizer-In...379337&sr=8-11

I would like something that just adds the right amount of fertilizer to my hose water without me having to think about it much. I have had hose heads with mixing tanks before and did not like them too much because I found them to be fragile and cumbersome.

I had heard mixed things about injectors from my orchid club. That said, the Hoss one has really good reviews. Do they work well? Some people have told me they apportion fertilizer poorly if the pressure is not high enough. Is watering plants in higher places a problem then?

I would be hooking it up where my hose connects to the water.

Also, if I do get one of these fertilizer injectors, is it normal practice to put a small amount of Physan and fungicide and water with that every time?

Thank you.