? Re: Switching filteration systems on existing tank

[PScoggin]

Greetings Fellow Reefers:

After reviewing this BB, I've found lots of info re: setting up new tanks/systems from scratch, however, this is NOT what I am contemplating... I have a 90-gal FOWLR system that has been up and running continuously for 16 years now. It is presently suffering from "old tank syndrome" due to some recent neglect over the past few months and a rehab (eradication of hair/slime algae and stabilization of water parameters) is in progress.

What I am considering in the near future (~4 mos from now) is a possible replacement of our (old) existing W/D filter/sump with a new "modified" (w/ protein skimmer) EcoSystem-type sump.

My question is: Can this be done on an established tank without completely disrupting the current ecosystem? In our existing system, a part of the filtration is provided by the LR and a part is provided by the aerobic bacteria that are currently living on the media (bio balls) within the filter/sump. While I would (hope to) leave the LR (and all other tank inhabitants... 3 sml fish + CUC) in place, what issues would I be facing with:

• Adding Miracle Mud/equivalent to new sump; recirculating 'til settled

• Removing the old bio balls from the W/D filter; removing the old w/d filter sump

• Replacing the old bio balls into the new sump (though in a EcoSystem-type sump, these serve a different purpose than in a W/D)

• Place new EcoSystem-type sump

• Place (Caulerpa sp) algae in the new sump

My main concern is that these two different types of filter systems rely upon different filtration components (trickling through bio balls in W/D vs slow flow through a planted algae bed) and that there could be a significant lag in the effectiveness of the filtration as I transition from the old to the new? This would, of course be "buffered" by the existing LR continuing to do its job during the process.

Any thoughts on the feasibility of this would be GREATLY appreciated.