Quick question - what's the weed called that you find in troughs?

[Faro]

I cleaned out one of my troughs last night because that green weed has been growing really rapidly, and it's been bugging me ever since what it's called.

Do you know the weed I mean, it has tiny little bright green almost heart shaped leaves, about 2 or 3mm across, and the leaves lay flat on the surface of the water?

Also, I'm fairly certain that it's harmless - and the horses don't seem to mind it at all. But if anyone knows any different, I'd love to know.

 

[milliepops]

Duck weed?

 

[emz1]

We had loads in one trough and the water was very clean underneath...seems to be keeping the toughs clean. Now some has been put in all the other troughs.

 

[angela_l_b]

The one that just floats on the surface is duckweed and is quite harmless. Most proper water plants don't harm horses - in fact they keep down growths of algae, which are potentially dangerous. If the water itself looks greenish then this might indicate algal growth. Otherwise anything that looks like long grass growing is fine, as is Elodea (the kind of thing you put in fish tanks) and Fontinalis which looks like a floating tufty plant but is actually a moss (also completely harmless). I have found all of these in various water troughs and they are ok.

Proper water plants take nutrients from the water so your horses are drinking lovely filtered clear water. However, high plant levels might indicate high nutrient levels which usually will be caused by a build up of old sludge at the bottom of the trough - just from things falling in (more likely if the troughs are under trees). If the plants feel slimy then it's likely that algae are growing attached to the plants (this kind is called periphyton and are still normally harmless). However, the presence of the nutrients in the water will encourage free living algae which might be harmful (blue-green algal blooms are thought to posion some animals). If there's a lot of sludge at the bottom it's worth a clear out.

All plants (including algae) need nutrients to grow, so if you take everything out and give it a scrub, it will stop growth for a while.

Oops - long reply! I have a degree in this... finally it's useful!

 

[Faro]

Angela, thanks! I don't think I could have got a better answer than that!