Fish can adapt to water ph \ hardness pretty well, what they cannot do is tollerate poison in their water, which is what Ammonia and Nitrites are, Nitrates above 20 ppm are also dangerous. While you cycle your tank, feed Bruce less. More food = more waste, more waste = more Ammonia. I feed my f8 once a day, until his belly is slightly distended, and I skip a day every week.
Brackish puffers are actually pretty resistant to poor water conditions, but keeping him in water that is not ideal will shorten his lifespan.
I was 'yelling' because in another forum when people found out I had Bruce in a 10 gallon tank they got pissed off and snappy with me. I was just trying to get across the point that I don't have the money for something larger.
Puffers are one of the more intelligent fish you can have, they are up there with Discus, and Cichlids. They get bored, they need area's to explore, and things to keep them active, changing their tank around weekly helps with these, or large empty snail shells, they will check for food in them often. They can easily see out of their tank, and can recognize several different people. My F8 for example can tell the difference between my wife, myself, and a couple of our friends, and he responds to each of us differently. A 10 gal tank is sufficient if the fish is < 1" in length from teeth to tail. Generally speaking you need a minimum of 10 gal per 0.75" of fish. Otherwise your filtration will be insufficient to handle his bio load, and you'll be spending more on chemicals and salt, not to mention changing his water daily. So keep an eye out for deals.
You state you are not an enthusiast, however if you keep Bruce around for any length of time, you will quickly become one, as puffers do have some special needs, other fish do not.
For example you will need to give him something crunchy at least once a week sometimes more to keep his teeth ground down. Give him about an hour with a snail, then remove the remains and discard, otherwise the snail will decompose and increase the ammonia in your tank, Shrimp are also good, if they are gut loaded, place them in their own tank, and feed them several servings of blood worms, so they provide nutritional value to Bruce. My LFS has an infestation of Ram horn snails that are about 0.25" in size, I went in for some starter shrimp for a breeder tank, and they threw in a dozen of the snails for free.
Something else you can do to save money, breed your own snails. An easy way to do this is to use an old gallon milk container, or soda pop bottle, or some other plastic container, cut the neck off so you can reach in and collect a snail here and there for Bruce, pond snails \ ram horn snails multiply rapidly, and do not need an airstone to survive, as they have snorkels they breath through. Feed them a flake food, and sit them in a sunny spot that will not bake them, and they will eat algae as it grows in the bottle. Change out half the water weekly - bi weekly.
Ghost shrimp are the same way, however they tend to be cannibalistic, and the small shrimp need to be separated, and fed small food to survive.
Brine shrimp are easy to grow however, they feed on algae, they require salt or brackish water to hatch, they reach maturity in about 6 weeks and breed rapidly, and you can go to Wal-mart and buy a "sea monkey" kit for around $5.00 once they are adults, let them lay their eggs, and feed a net full of the adults to Bruce. They swim pretty quickly, and Bruce will enjoy the challenge of hunting his food.
Baby brine shrimp also make good food for baby ghost shrimp.
Total cost of each breeder setup is less than $5, and you know the food you feed Bruce is safe.