Marine to tropical

Question
Hi there - I am moving house and have to relocate my 40 litre tropical tank. Fortunately, I can do this over a period of weeks. I got a good deal on a 90L tank that had been used for a marine setup, complete with Fluval filter and lighting canopy.

The new tank was dry when I picked it up, so I have filled it with RO water and about 5L of change water from the tropical tank, plus a bit of real wood from that tank, in an effort to start it cycling. I can monitor it but wonder if I need to change out the filter material (sponges and some ceramic hollow tubes) in the Fluval or if they will be OK. I'll add some more change water from the tropical tank next time I change it as well.

I've often considered a marine setup (like a red Sea Max 130D) but I go away for a month in the winter and while it's easy enough to get someone to feed the tropicals for that time, I suspect no marine setup - no matter how sparsely populated with fish - is likely to survive a month's abandonment? Thanks - Steve

Answer
Hey Steve,
I would change out the filter media(sponges), and just rinse the ceramic meadia thoroughly. It'll be fine after that. You're started in the right direction, using your existing systems water and taking your time, both great things for a move.
A marine set up, left for a month... it can be done, but you have to have the right kind of filtration and a reliable person to feed. Marine systems just require more filtration as the fish(in general) produce more waste. So a large volume, strong flowing sump, with automatic top-off, automatic doser(liquid supplements, minerals,vitamins, plankton, etc) and a sg/water chemistry monitor can enable lengthy trips, but these systems get pretty pricey and if it's only a month each winter... I would look for a trustworthy friend to possibly do it(and what if there's a power failure?) or just wait. Even a set up as nice as the 130D would require additional volume(big sump), flow and filtration to remain stable, with someone doing only feedings. Hope this helps.