Tank is in transition state now. Sold 2 gigs 3 weeks ago, the original blue gig this thread was started with and a purple that was crowding the green. Here's a pic of where it is today, which will change again in the coming weeks. I got burned bad from the gigs when removing them 3+ weeks ago. No gloves, my right hand and arm were on fire for days, and I still get sick feeling every day from it, even though it's 3+ weeks later. They are definitely toxic, I've never had a reaction to gigs all these years like this.
Check out this fat tent on a purple. It's got tents growing out of the sides of it like it's an anemone of it's own.
Here's the 210. I'm going to be upsetting both tanks in the coming weeks/months, both are in need of major "tweaking" and cleaning. Overflows are all clogged from worm growth. The sand in both tanks has solidified. The rocks lift up with the sandbed as one. Time and funds may put the 75 in jeopardy of existence.

Mertens has decided to start to go for a walk. It's been a pain trying to get it to accept the same conditions as the gigs. It may go into the 75 by itself, not sure yet. It's not happy right now.
Side shot
One of my thoughts is, get all my gigs (that can fit) into the 210. I have a filter sock that I can clean all overflow water with. When time permits, I can take a filter sock out, turn it inside out, and give it a tank of it's own with a light for a few days and see if anything that resembles a gig appears. This won't happen fast, but still gives me an opportunity to look forward to something, the joy and fun of rehabbing gigs for me is over now.