3. Upgrade the filtration – Prior filtration was accomplished by a small 7 gallon or so in-sump segmented refugium and an in-sump Excalibur SV1 skimmer. Although this filtration was adequate and I had REALLY good luck with what I consider to be an excellent little skimmer, I felt it was time to step up to something with a little more power. I purchased a used ETSS 700 with a Mak4 pump. A little dirty - but at about 3 feet tall - it's more than sufficient for a 90 gallon.
