I don't expect it'll be perfect on the first go. But there are many things that can be changed later and a few that absolutely cannot.
My goal is to make sure the design is not pigeonholed.
For example- I can build a greenhouse, but if I build it facing south, I won't have sufficient light. The greenhouse must face south. Not really fixable.
The wind in TX flows south to north so my big doors and vents are in the right orientation to leverage that flow for cooling. I could build it with east west doors, but it would cost $10k+ to fix later.
I can go with standard glass, but that would block 40% of light especially the high blues, violets and UV. The result would be brown ugly corals most people associate with solar lit tanks. Also fixable later for $10k+.
I could go with air ventilation cooling only, but the calculation show that the greenhouse would become a sweltering 105F 100% humidity zone with fogged up glass and dead bleached coral. Nothing a $10K HVAC can't fix, but I'm laying out 200ft of underground pipe for an air cooling loop under the greenhouse slab. That would be impossible to do later.
I'm working out the tank dimensions to maximize grow volume at 12' x 8' x 27". I could go smaller and then start over in a few years or be perpetually sorry I didn't do it right.
There are some things that I could have done later, but would have required draining the tank. If I put the right "hooks" in up front, I have the flexibility to evolve over time. A good example is the powerhead flow vs vacuum pump flow... I don't know which is better so I'm going to build the tank so either will work.
It's the difference between permanent and modular flexibility.
I guess what comes across as over thinking is really just me future-proofing the most expensive and least changeable elements.
When I think of how I wish I had designed my current tank, I kick myself every day for locking in some key elements that would have made it spectacular.
But you are correct: in the case of locking out the dark zone - it really doesn't have much a penalty to change later... so you're absolutely right on that one. Well, except a big tang that gets locked in the dark zone and dies of hunger... or the decimation of the shrimp population. All fixable later without massive expense though.
I do like to share ideas and conversations that come up... you may have opinions or thoughts and I'm a believer that the collective is smarter than the individual... so I ask
![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)