many use it with good results.
More use the generic gluteraldehyde with the added bonus of $$.
Glut is 2 1/2 time stronger on average and 1/2 the price at most! http://www.ebay.com/itm/like/1414039...ectorid=229466
Excel/Glut are incredibly useful as a carbon supplement and algaecide. For how useful they are I'd just skip the 1% of plants they negatively affect and instead let the rest of the plants out there reap the benefits of a very useful product.