Garra Pingi

I need a cleaning and my tank is a mess

Well, they are cold water fish, so if you have a cold water reservoir and then click Yes. If your tank is tropical, you could get a pleco or bristlenose Otocinclus few!

yes, that one gallon as long as you stay in regular cleaning of the tank you should be fine.

In addition, this site shows that the minimum is only 20 gallons, Just So You Know.
http://www.aquariacentral.com/species/db ...

depending on how many fish you already have in your tank you may be able to have one. 29 and 30 gallons is almost the same size, if you have a few small fish, you should be able to have one without any problem.

Yes I think its fine.