Is This House Plant Food Or Something Else?

[betta fish]

I'm wanting to buy some root fertiliser for my aquatic plants and have seen this for sale seemingly for aquatics http/www.robbinsaquatics.co.uk/index.php?main_page=product_info&cPath=116&products_id=280 this looks identical to the pellets I see for sale for house plants where you can get 10 on a board for the same price, although am I right in thinking house plant feed is not to be used in a fish tank

 

[Carlovel1]

Aparently, its Aquatic plant fertilizer but it looks quite dodgy to me
Go for TPN root capsules instead

 

[BackToTheFishes]

Too good to be true at that price?