Can this hold tanks?

Do you know the weight rating of the unit itself? A lot of times they have a maximum weight limit, and then it should tell you a per shelf limit (since that particle board/wood can only hold so much).

From there it should be easy to tell if a fully stocked 10 gallon would work on multiple shelves.

I’d check to make sure that the manufacturer has a weight listed per each shelf, since the whole unit may be able to hold that weight but each shelf can’t hold enough for a decent sized tank.

Yeah, you need the per-shelf capacity.

The steel shelving units we have at my work can hold pretty heavy amounts, provided the shelving unit is anchored. That pictured unit looks like it might hold the weight, but one cannot be too sure about it though.