i would try it failed nto that you dont want it.
What do you use and is 48g to much pressure on plastic for consumers?
i have used smaller ones and bigger ones nothing around that size. personally i would hit up monster fish keepers and look there. there are a few people on there i know who use plastic bins for temp fish tank. the admin over there has a bunch of them that are plumbed together for a auto wc
i would check craigslist for some time of water storage container. i have some 240 gallons some 100 gallons for soaking wood and spawning livebearers and a few 20 gallons that i use for qt when i am in a crunch.