I assume you have drywood termites and not one of the other species like the Formosan termites (super termite)?
I have had success with localized treatments for drywood termites as opposed to the tenting for most situations I have encountered over the years. In Maryland drywood termites do not survive the winter, but if brought in from the south, in furniture or what have you, they can survive in heated homes. So we occasionally need to deal with them.
One good thing about drywood termites is that their colony size and extent of damage occurs a slower rates than the common subterranean termites or worse yet the Formosan (super termites). If the infestation is not out of hand, I would pursue localized treatments by injecting into the colonies with aerosols using straw attachments. If necessary, opening up walls or flooring areas, perhaps ceiling areas to get to the infested areas is worthwhile IMO. Usually they spray all the wood surfaces with Termidor or a similar product.
After a localized treatment, you will need to keep an eye on the infested areas (perhaps the rest of the house as well) to make sure you get the drywood termites. Drywood termites produce very distinct fecal droppings which the termites kick out of their galleries in piles. Swarmers occur normally during the spring and one needs to be able to identify the species from the wing patterns to make sure they are not a subterranean termite or others. I have seen cases where companies were in reality fighting two species of termites and couldn't ID the swarmers. I have seen companies fighting drywood termites and thought they were subterranean termites. This leads to problems for the homeowner until they get someone out their that knows what they are doing.
Regarding your fish tank. With a localized treatment you can get by with covering the complete tank in plastic and turning off the air & water pumps for about 4 hours. Make sure you keep windows open if possible. If you go fumigation route, you will have to get the tank out of the house.
Good luck and if you have questions let me know.
