water topoff

[mytank90]

i am getting tired of haveing reset my skimmer and haveing salinity move around and looking to get a topoff system going .thinking i will try the tunze one .i have enough room for roughly a 10 gallon tank if custum build or i could buy a 5.5 gallon one from self .would bigger one be better or does size realy matter for topoff ?also do you need run a small wave maker in one to keep water moveing?right now i loss about 3 to 4 gallons a week to evaporation