.. oh and two UV filters...
The water was crystal clear and the Corels and fish loved the current. Water stability was great, as were all stats except Nitrates which were high.
After some thingking and visits to LFS, we though it was the two central bio canisters. Foly filter was used for a while, but it only helped so much and is expensive.
The tank never had a sump, as we didnt trust an over flow box, didnt want the wooden floor damaging (If only we knew, but his house not mine so...) and as we built the tank we did not have the skill / tools to drill it. we could not find anyone locally either.
Sealed canisters it was. ... but we longed for a Fudge ......