Sorry, to not give a helpful answer to your question, but rather raise some further questions...
Which specie of Pangasius would that be? Some species of them grow to GIANTS (3 meter or near that), and they are active swimmers, so need some decent swimming space.
In fact, the species listed in the Cat-eLog will all grow to MORE than 30 cm[1], and most will grow to a meter or longer. Anything that grows much beyond a foot becomes very unpractical for anything but public aquaria, as you need a tank that is more than 2 foot wide/tall as well as more than 8 foot long. Outdoor/indoor temperate ponds would work reasonably well, but of course it makes viewing the fish difficult. And ponds are even harder to move than aquariums, should you decide to move from one house to another.
[1]
is listed in fishbase as 30cm SL, but a photo of a fish [also in cat-eLog] shows the a fish next to a 30cm ruler, and the fish is easily 45-50 cm SL, around 60 TL. This is fairly normal, as Fishbase uses scientific records for their sizes, and it's a well-known fact that scientists will often collect only the smaller specimens of a specie, for several reasons, one of which is that they aren't able to preserve large specimens - or they wuld rather preserve half a dozen small ones than one large...
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Mats
and wanded a troup of cleaners for the aquarium. i tought corydoras were a bit too small and would be killed 
so i tought of putting a blue lobster in. if you have any suggestions of cleaner fish i can put in please reply
