I did use Cidex for BBA and it kill them! And it is cheaper than Excel!I should say that I got a similar experience.
I have a non-CO2 tank that has been clean for ages but the last 2 months or so I started adding Excel in a dose about 5 times the recommended about every 3 days.
Things were great no algae with the exception of very few bba spots.
After stopping the Excel bba, bga, and hair algae appeared.
I started dosing again and all 3 algae disappeared, only the bba is still there but less than before.
Вы говорите по-русски?