This is my first post on the forum having been a member for a while now. These pages have been a great help in my planted tank initiation but ive now found a subject i cant seem to find much information on - treating algae with amoxicillin. Firstly a bit of background on the problem: After a few months working in a LFS i was given the privilage of seting up a planted display tank. But i didnt exactly decide to do things the easyway, opting for a scaped design with plants: HC, C.crypts, Hairgrass, and M.micranthemoides. I had to use the 'package' that comes with the tank - Interpet PF2 internal filter (yes i know, its a bit on the small side!) and two T8 lights on a 110l aquarium, all with this being my first ever planted tank. Safe to say things got off to a slow start! but with the addition of two T5's and a CO2 kit things got going. The problem is the staghorn algae that decided it likes the HC. This was caused along with a few other little 'hiccups' along the way by a few things - including some over zealous filter cleaning = ammonia spikes which were aided by the fast growing messy group of bentosi tetra (now rehomed), inconsisted CO2 levels (when it was put on there!) thanks to a dodgy old valve, some diffuser experimentation, and my general inexperience! The tank has now matured nicely (and ive learnt i little from my mistakes along the way!) but the staghorn algae is a permantent fixture, as manual removal - destroying the carpet is not an option. Ive read of the use of products like Excel in conjunction with manual removal being used as a remedy...but i cant seem to find much info on the use of amoxicillin to kill algae. I have seen it for sale on american websites for this purpose. As i (think) i understand it the amoxicillin inhibits one of the metabolic pathways involved with photosynthesis within the algae, stopping energy production and ultimately resulting in death. As far as im aware in the UK antibiotics have to be prescribed/administered by the trained/qualified people. Does anyone know - if im correct and does this mean there are any legality issues with its use? - what kinds of algae it will treat? - if it will affect higher plants? - if it will have any implications on the health of the stock (inc.shrimp) or filter function etc?