First off, I know overall they are Chinese crap but my budget right now (Christmas with 3 kids) doesn’t permit buying a high dollar unit. I have a 150G cube and I’m trying figure out which one to use so I don’t create a sand storm. I’m torn between the OW-40 and OW-25. My tank is 40 inches long but 30’ wide and 31’tall. If I had a 72’ long tank I wouldn’t be asking but here I am so let me know what you think.