Of course. The only hassle is the depth of the tub. What I would do is to get some compressed bales of sphagnum moss or peat moss. Sit them in the tub, put in a stopper, and fill with rain water to let the bales soak for a few days until they are soaking wet.Pull the bales out of the tub and let drain off. Then find a stopper that is a little smaller to fit in the drain hole so that the water will slowly leak out of the tub, provided you have the tub sitting on top of the ground. If you plan to bury the tub to its brim then lay in a foot or so of gravel before placing the tub into the hole. Once the smaller stopper is placed into the drain hole, take the bales of sphagnum and/or peat moss and pack them into the tub. I use my foot to pack down the moss. You should have enough packed in to fill up to about a foot from the top of the tub. Then have some more peat moss that has been soaked and drained handy to mix with river sand in equal portions. Pack this mix into the top 8 inches of the tub. The top of the substrate level should be about 3 inches below the top of the tub. Fill with rain water and then let the water level drop below the surface of the substrate before planting your bog plants. You can poke along the side of the tub down into the substrate to see where the top of the water level is. Once it hits the packed in bales refill water to the top of the substrate.

xc60 - sounds great - I know just enough to be dangerous. I love this forum. I learn more from it than going to the plumbing showrooms. katmomma, you will have to search this forum for air tubs. I can help you with selecting drop in tubs based on shape, size, quality. You basically want a good quality air tub without the price tag. Mirabelle tubs are well designed, deep and I see that folks on this forum have purchased them as air tubs. They are private label for Ferguson (made by Clarke). I like the feel of their acrylic better than Kohler. I don't see folks talking about Kohler air tubs but they make a solid whirlpool and are priced right. I do not know how the Jacuzzi air tubs are but I personally like their designs - they are priced right for you too. Jason, owned by the former Jacuzzi folks, can get pricey. Same with MTI, Hydrosystems, and Americh. Maax tubs are nice but I see on this forum that folks say that their air tubs are loud.

My grandma eats sweets including homemade pies with 1-2 c sugar per pie, loves sweets in general, eats too many fried foods for my taste, doesn’t eat paint chips, bathes in a porcelain tub, and was JUST moved to a nursing facility this year since she’s losing her mobility (mind is still intact) and in another month she will be celebrating her 100th birthday. You don’t have to live in a bubble to live a long life. Much of your life expectancy is predetermined in large part by genetics. Use common sense and don’t lick the bathtub.

For a jetted tub used as a shower, it has to have an integral tile flange. That allows the wall cladding to overhang and any water that hits the wall to not go behind your walls. There aren't that many in that size that are inexpensive. It will need a specialized drain, and, if you want to spend any time in the tub, a supplemental heater so the water doesn't cool off so fast. Since it's a tub/shower, the wall cladding will need to be redone to be waterproof into the tub. It's possible, if the build is recent, and it was done with the proper vapor barrier behind it, that only one row of the tile would need to be pulled in order to replace the tub. But, I wouldn't count on that. I'd count on having to replace all of the wall cladding in the alcove. That can be as cheap as a plastic surround for around $100 or cheap tile with the proper vapor barrier for probably $150 or so. The first is the easiest and the least chance of leaking. The second will read as more upscale, but you have to be sure your contractor understands about the vapor barrier and correct materials to use to tile this (NOT mastic.) And since you have that torn out, it would be foolish to try to keep your current control valves for the bath unless they are also very new. New safety standards are in place for anti scald mechanisms. So, you will need a new shower/bath faucet and valve. Then you will need the electrical line run from the panel to the location for the whirlpool pump and supplemental heater. That location is usually opposite the drain side of the tub. You will need to be able to site an access panel that is removable to be able to get to the electrical innards here. That can be from an adjacent room, or from a hidden panel on the tub itself. All in all, you might be able to get all of the needed materials for 2-3K if you shop the box stores carefully and find some bargains. The danger to that is that if you are inexperienced, you don't know if you're buying quality or crap. They sell both. And that's one reason that it would be simpler to let the pro pick the products after you tell him the features that you want. Then you've got to pay the contractor labor to install all of that. The electrician's price will depend on how difficult it will be to access the panel and run the wire to the location. For that, it's a really good thing you are on a crawlspace! That makes it cheaper for both the electrician and the plumber. On the whole, I'd expect your project to cost between 5-7K, depending on location, and if you have no DIY skills to bring to the table and have to hire professionals for the whole job. And be sure that you hire someone that is licensed and insured to be in your home, and will pull the proper permits to get the job inspected with your code office. Some handyman guy isn't licensed to do electrical of that nature, and while he might be able to do the demo and get the tub in place and glue on the plastic surround, it's unlikely that he'll have the right insurance to deal with a large job like that, and thus probably wont' want to pull permits and be inspected. They are usually limited to smaller jobs like simple fixture replacements like a faucet or light. Which this isn't. Just remember, you are doing a project that combines electricity and water. You really have to know what you're doing here! A small General Contractor should be able to do the complete job, and also carry the needed papers. And he should have no problem with the code guys coming in to inspect his work either. If he does, then he's not the right person for the job.