R. Santink wrote:

They've been growing rampant for over a month, whether shaded or not.
This has all of a sudden happened. The only chemical change I've made
is the addition of Seachem's Excel.



OUCH. See this link:
http://www.seachem.com/support/FAQs/...Excel_faq.html

Search for 'anacharis'. I was guilty of this before. I still use
Flourish Excel, but in far less quantities.


Ah ha! I always knew there was an explanation for everything. Thank you
very much for that. I will half the dose and closely monitor the situation.

Nikki