Caulerpa is a macro algea often times utilized in a refugium for the purpose to control nitrates and others...the caulerpa consumes the nitrate thus exporting it from the water.
There are a few different types of caulerpa as well...
I understand you Reefnut...like I said he was pretty much blasted for the advice he was providing by numerous people...I think he understands the importance of providing advice based on tried and proven techniques...
His posts are curiously odd though, he does sometimes misrepresent the truth...
I think it is cool bob that you are continuing on with your ways...and I encourage you to continue to do so...I dont encourage you to give the advice you have, but that has already been discussed...
What many of these people apparantly fail to realize is that our hobby was and for most parts...
You could try some 1/4" acrylic and make a strip out of it...form it to fold over the front and back of your tank. You could probably even use a thinner acrylic and attach it to the remnants of the old center brace.
For one of my refuge's...I made an overflow box out of two plastic drinking glasses mounted to formed acrylic holders, placed on either side of the tank with a hole drilled/cut in the exterior one to accomondate a 1"pvc screw in with silicone...the ******** side I cut a section of the glass lid...
Finland is correct on the caulerpa...the Mangroves are usually kept in a refuge due to the fact they have to grow out of the water. If you are intending on putting them in your display tank, ensure there is enough room between the water surface and your lights to accomondate this.
Generally they will ship 1-2 days after you order...unless you order early and it is mon thru wed i think...i order on thursdays, they ship it out mondays with tuesday delivery...
All their livestock travel next day service.
Maybe take your new liverock out...put it in saltwater with the salinty about 1.040 for a couple of minutes...this should cause any hitchhikers to evacuate the rock...in the event you have any