Usually 20% mixture is okay little less not a problem.
I'd filter the antifreeze could have crud in it you don't want.
Second that. I remember running antifreeze in ice bath loop for giga bot comp a few years ago and had to do a total cleanup on all parts. Its not the antifreeze per say, but the effect it has on tubing. Rubber is okay, pvc or like is not. It eats at the tubing material and gunks up blocks and pump over time. Nasty mess.