I'm running pihole on a raspberry pi zero w for some weeks now.
Unforunately it wasn't possible for me to run it on my rasp pi 3B+ running hassio as an addon. I some issue that nat loopback wasn't working right. So had to chose between an inside and outside (local network) url each time.
So someone in the home assistant forum told be to install pihole on a seperate device. So I did this and bought a pi zero w.
So I'm wondering now if pihole on a pi zero w will slow down my network, because it is connected wirelessly with the network.
Should I worry about that? Should I change something in my setup.
Best thing would be if it runs on my hassio instance, because this one is connected via ethernet and all would be on one device.
It should not. The only traffic that the Pi Zero W is seeing is DNS traffic, which is very low bandwidth compared to the actual data going on your network (a typical DNS request is a few hundred bytes at most). DNS requests go to the Pi, but the traffic between the client and the resolved IP on the internet goes directly between the client and your router, with no route through the Pi Zero.
The Pi Zero W is a popular choice among Pi-Hole users.
Note that the Zero W is wireless on the 2.4 GHz band, which is generally a more crowded spectrum than the 5 GHz band. If you have difficulties on your network with connectivity from the Pi to your router, you have the option of using a USB/ethernet adapter to connect the Pi to your router via cable. I have installed Zero W's for various family and friends in environments ranging from urban, suburban and rural, and none have had any wireless difficulties.
Good to know that it will not affect my network speed. Nevertheless I will try to make pihole work as an addon on my ha instance to get rid off one device.