These tanks were either gifted or old ones sitting around. I will give you sizes and dimensions and you guys can please let me know if they can be used for anything. Please also mention any specific species or specific limitations related to the size of these tanks as well. Thank you in advance... Here are the tanks:
1- older "bread display" acrylic. 15.25" wide x 16" high x 14.25" deep (on big/low part) that "angles" to 10.25" deep on top side. There are three acrylic shelves that mount inside that can be taken out and it is back opening... And also that peace would need replaced as it is broken. I've been toying around with ideas with us for some time so if it is not able to be used then I will not be surprised but if it is then that would be great! Let me know.

2- 5 gallon tanks are 8.75" wide x 16.5" deep x 10.25" high. Standard 5 gallons, 1 with lid and 1 without (if it matters lol). Will this work with anything?

3- old saltwater holding tank, turned "bare" is 7" wide x 19.5" deep x 11" high (thin 10 gallon basically). NO lid at all....but if I could fashion something, would it work for anything?

Again, thanks in advance for your time and efforts...AND if you feel that these are gonna be just plain UGLY visually, please let me know and I'll just pass on then for that reason and not even use them. Can't wait to hear back! Thanks!