deranglerhaken

My Mattenfilter works primo.I put a picture frame around my tank and planted the foam with javamoss and ferns.the older the better it works.you can always put it in as a corner filter.all my tanks got one.very cheap just the foam ,i bought a whole sheat 2m*1,2m for a 100 bucks last me a lifetime and does a lot of tanks biggest one 640 litres.

Check out the "Hamburger Mattenfilter" just put it into google search can't remember the websites.very popular in germany and yankee land befor all the hightech crab came in. It a 5cm porous filterfoam(little bit hard to get here in Kiwiland) It works like magic never have to clean it.And you can plant it so it blends in.Worth looking at it.

Just use scoria/lava rocks.give em a good scrub,so.they are really porous

If you got a lot of plants in your tank I would fit the spraybar under the watersurface so not to disturb it and loose CO2.

What about Soda-Stream bottles.Every garagesale or fleamarket has them for a few bucks.The problem is to get the gas to release slowly.need needle valve.