I have had a canister filter for almost 2 years. I am changing over to a sump. I purchased a wet/dry filter (attached) and added a baffle.
What I would like to know are the steps I should take to make the transition smooth and harmless for the reef? Also, I am scared to death about a flood. What steps can I take to prevent that from happening?
How large is your tank? Does your current filtration (canister filer) contain newly replaced media? or older media?
Your #1 issue is removing so much current beneficial bacteria that your tank can no longer support itself and it crashes. So we can trick the tank in a couple ways.
1) Grab a filter sock or mesh bag, and pop in as many bio-balls that you have in your sump picture. Place them in the tank for about a week. This will allow beneficial bacteria to get on those bio balls for when you make the transfer to the sump, which is a good thing.
2) Get some filter sponges or MarinePure Blocks and do the same thing.... place it in your tank for a week or two. Again, this allows bacteria to get on the blocks and transfer over.
In my opinion, the above two options will allow you to remove the current canister filter, while transferring over as much of the beneficial bacteria as you can. Sure there will be a small loss, but not so much as to cause a crash. For the first week, cut back on feedings slightly so your tank can play catch up, and then you should be good. Also monitor your water perimeters, do a water change if needed.
Now in your head, trace the flow of water from the overflow, to the sump, return pump and then back to your tank. Know how it will flow, where it will go and you can prevent a flood. Realistically that sump was pre-made so there is nothing really I can see to cause an overflow apart from the return lines maybe causing a siphon. Make sure you drill a hole at the bottom of the return line (just below the water line in your display tank), so there is a siphon break in the event of a power outage or you turn the return pump of to service your tank.
