Make Your Own Betta Cave

Edit:  See final(ish) version of the betta cave toward the bottom.

I have this El Niño fern in my aquarium and it's not doing so well, so I'm hoping it will help if I can get its leaves to stick up out of the water a bit as it acclimates to being fully aquatic.  It's not looking horrible yet, just losing some of the green in its leaves.  I really should have learned more about caring for ferns before I got it, and I should know better, but it was an impulse buy on a trip to the Pestmart.  As it is, the rhizome is buried in the substrate, which is a no-no with ferns.

Here's a picture of the fern.  It's the dense green fern behind the cave on the right.

My original plan was as follows:

Thankfully a member on a request for help at Tropical Fishkeeping mentioned that placing a fern in a flower pot would probably not allow enough water flow around the rhizome, so the idea morphed into this:

This is what it looked like after I set the hole in.  I've seen a lot of people using a hammer and chisel on flower pots, even soaking them in water for days in an attempt to "soften" them.  I have not had any luck whatsoever with this method, so I pulled out my trusty Makita angle grinder and Bosch diamond blade and went to work.  I did have to file the edges smooth by hand.  Note, I also used a masonry drill bit to place a hole in the dish above the flower pot.  The hole mates with the hole already in the flower pot so later I will be able to tie a piece of driftwood above without having to soak it for days on end before it sinks naturally.  The two pieces are held together with aquarium sealant.

After the bond between the upper and lower pieces had cured, I put aquarium sealant all over the exterior of the pot, leaving the inside of the pot and the top of the dish clean.  I then covered the sealant with gravel of the same color and brand as my substrate.  You will want to press the gravel into the sealant a bit so it sticks better.  When it was done I could still see a lot of the green pot between the pieces of gravel, so I knocked off the loose pieces, coated everything in sealant again, and and applied another coat of gravel.  This is the final product, right now the project is in the final curing phase.  

I will be sure to post pics once I get the driftwood and fern tied on and the final product in place in the aquarium.

Here's a picture of what it looks like almost done.  It has gone through several revisions by now.  All I need to do is finally rinse some more gravel and place it in the top tray.  The el niño fern has been tied to the driftwood with fishing line.