Follow-up: we left the water lettuce in place in the pond. At first the amounts were increasing, but once the fish got hang of eating them they quickly disappeared. There are just a few odd ones left, the rest turned into fish food.

We also have water lettuce in a smaller pond (where the gray water from the septic system comes out) - less fish there so that one has to be cleared every now and then. I try to keep it at 50% surface covered by water lettuce, 50% open.

Lingling - What kind of fish do you have in the ponds that are eating the lettuce?

rgds

Lingling - What kind of fish do you have in the ponds that are eating the lettuce?

We have a mix of fish so I am not sure which one(s) are eating the water lettuce, but possible candidates are Pla Raed, Pla Nin, Pla Duk since we have a lot of those. There are also supposed to be some japanese carps in there but I don't think they have survived. (never seen any of them but we released 200 of them a few years back)

Im impressed, I've been gathering info on greywater & rainwater collection but hadn't considered doing anything with blackwater.

Whats the water like as it comes out of the septic tank, smelly at all ?

So far it is "clean", but it is a new built system so we'll see what happens when it has been in use for a year or two. But in general, I would think that using green plants to eliminate nutrients should be a lot better than infiltration or similar.

Lingling - What kind of fish do you have in the ponds that are eating the lettuce?

We have a mix of fish so I am not sure which one(s) are eating the water lettuce, but possible candidates are Pla Raed, Pla Nin, Pla Duk since we have a lot of those. There are also supposed to be some japanese carps in there but I don't think they have survived. (never seen any of them but we released 200 of them a few years back)

Probably the pla raed, and pla nin. Not the pla duk. Thanks

rgds

Im impressed, I've been gathering info on greywater & rainwater collection but hadn't considered doing anything with blackwater.

Whats the water like as it comes out of the septic tank, smelly at all ?

So far it is "clean", but it is a new built system so we'll see what happens when it has been in use for a year or two. But in general, I would think that using green plants to eliminate nutrients should be a lot better than infiltration or similar.

I thought I'd revive this thread with all the talk of septic systems going on in the DIY forum.

Lingling, how's the ultimate recycling system operating now it's had a few more months to settle in, a success??

EDIT Lingling not seen since July, hope he didn't fall in and get consumed by his fish

Apparently mosquitos like to breed in them, and the fish can't eat the larvae when they are inside the water lettuce. So maybe mosquito risk...

Here's an article about using it as pig food:

http://www.cipav.org.co/lrrd/lrrd14/1/ly141a.htm

Pigs love "pak boong" Apparently it makes them "cool off" after eating it.