Have my air-stone place at the opposite side of the powerhead so wont air lock, thanks for reminding!
But sadly, i don't have a canister filster yet, saving to get a cheap one. i heard Jebao is OK(about RM160-200)? and i saw Fluva have the 403 and 404 series selling at some shop, think price is range from about RM200-300(if not mistaken).

wonder which i should save to go for...
Thanks, will let you know if the aeration method works for me.