These are great as long as your reg has enough grunt to run them 2-3 bar same as the inline atomisers ime plus they will clog over time so best to replace them every 6-12 months in hard water areas I've found.I use a Fluval and it works well, I'd still like smaller bubbles though. Has anybody had any experience with these? http://www.aquaessentials.co.uk/easy-aqua-super-mist-atomiser-small-p-5571.html