How do you do this? I want to check alk frequently but only when the lights are on. I could care less about b/c. If I could only test Alk that would be great.
I got some recently from us plastic. I got 1/8id 1/4od to replace my kamoer fx-stp tubing. Not sure if that would work for you. I only got 5 feet so, I don't really have any to spare but here is a link.
Link is here. https://www.usplastic.com/catalog/item.aspx?itemid=22671
If you can find one of these used (they have been out of business for 3 years) it works very well. It is what I am using for an auto water change. https://reefs.com/product-review-genesis-reef-systems-renew-part-1/