Backyard Aquaponics
A place to discuss aquaponics

I just had a friend come around and give me a heap of "Purple lilies" for my tanks that are in full sun , he said they did a great job clearing up the water and stopping the algae in his pond & he had too much , so ...

turns out theyre Water Hyacinth , an invasive weed ...
( Oh no , if the council found out I had water hyacinth .. they'd also find out I had fish , and open ponds , and rabbits , and chickens within 9m of a habitable dwelling , and a roofed structure within 1m of a wall , and the gall to grow my own food , etc ... )

Is ANyone growing Water Hyacinth in their systems ?
Ive read up a bit & so far found out

a) supposedly they deprive natural rivers / lakes of dissolved oxygen once they take over . Im assuming that wont be a problem as oxygen transfer through water surface is the least of the methods of oxygen input in my system - Flowing into / out of the growbeds , plus the submersed pump with venturi fitting

b) Theyre amazing at collecting and removing heavy metals from polluted water - I read that some water plants in the US were using them to remove cadmium , mercury and lead with great effect . I guess I cant possible tell what nasties Ive got in my system , but if theres any heavy metals I dont know about ,this stuffs gonna get rid of it

3) damn unkillable - large number of seeds per flowering , then they drop to the bottom and keep for years . burning & poisoning only kill the living plant , the seeds can keep for a number of years and can survive drought and salt water . I figure if I cut off and burn every flower before it goes to seed, then I'll be able to keep the thing under control

g) They provide somewhere for mosquitos to flourish - I assume thats due to the way they take over and "mat" any waterway theyre in . Shouldnt be a problem as my systems are all infested with Gambusia now anyway

Just tried out a leaf on one of the sacrificial rabbits - it wolfed it down . My mate says back in his home town its used to feed pigs with great results - bigger , fatter pigs quicker than on normal ( whatever that is ) pig food , so I figured it'd be alright for the pets . Chickens didnt want anything to do with it though ( although , theyre scared of bread and just stare at snails , slugs , slaters etc )
Im planning on feeding a little to the rabbits for the next week , then getting rid of excess growth for a couple weeks after that while the plants suck any heavy metals out of the system ( dont want to feed that stuff to the pets ) before I start using it to feed them full time

So far then , my only concern is that the water hyacinth is going to block out the duckweed in the two tanks that Ive put it in , not that it really matters as the duckweed grows much faster in the other system anyway

Theoretically it'll grow fast , block out the sun and get rid of my algae problem , thus my pH swing , cover the water so the silvers dont freak out every time I walk over to feed them ( thus theyre not eating ) , suck out heavy metals that I may have in my system ( not that I think Ive got any ) , plus provide extra food for the animals

can someone give me reasons not to grow this stuff ?

the roots are looong, the plant will look about 60cm tall and the roots will be about 1m long underneath as well. you may have issues with them blocking the pipes etc

Here in Florida I know it is highly illegal to have the stuff in any way shape or form. It tends to choke up waterways and push out native plants while slowing flow rates and causing flooding problems up stream. Up in Michigan it is great stuff for the ornamental pond though it is often difficult to get it early enough in the season for it to have a chance to flower.

I've heard it can be edible but only after repeated cooking in changes of water or something like that. You might do a little more research on it to see how safe it is for the rabbits and such.

It is great stuff for using up nutrients in the water, if you have lots of it in your system, you may find you don't have enough nutrients to go around.

Ive read that Tilapia eat the roots , hopefully Silver Perch do the same

it dies back a fair bit in the colder months ( around here anyway ) so it shouldnt pose a problem to the trout Im planning on

On the nutrient problem - The plants Ive got in the growbed in this system arent doing too well because of the algae problem / pH swing , so if the Hyacinth takes out nutrients now its not a problem , then if it blocks out the algae and stops the pH swing I'll start cutting it back as the other plants take off

I'll keep an eye on it and report back once it causes problems

hmmm one of the world's worst weeds...I think you're mad (and you might have more than council on your tail if caught ) but good luck

I have no doubt they cleared up his algae problems... because it would have choked out everything else in the tank.
we had a plague of that stuff up in north qld a few years back and it covered about 2sqr km of lake, and when it all died it formed this solid festering raft of rotting matter *yak*.
my advice, burn that sh*t.

It's a perenial, so must have been poisoned in that lake in FNQ.
Makes great compost too - just make sure it's a hot compost >70 degrees C which will cook the seeds, then use it on the dirt garden where it won't germinate (or if it does it'll die of thirst).
Declared a noxious weed in Oz and big fines apply if caught ..................

McFarm, Spec for pasteurising compost is >55 degrees a period of 3 consecutive days. I think it's 3 days anyhow.
Maintaining an average temp above 45 for a period of 14 non-consecutive days is also good to keep other evils away.

my greenhouse was +55 for 3 days, I didn't see many nasty things dying

Only reason I chose 70C is that I've found that my smaller heaps <1m3 peak at over 70C for 24 to 48 hours and then settle down to coolish high 40's, and they cook all seed if turned and allowed to reheat. Very much depends on composition/content though and getting the Nitrogen Carbon mix roughly right. Not sure why but my larger heaps are always coolish 40's to 50 's and take forever (well weeks anyway) to cook - too much carbon I guess. I know neither is the ideal, but they work for me. Never had one combust though - that would kill em.

Anyway no disputes on specs, and as your post alludes the higher the temp the shorter the time required to kill seeds. Also depends on seed type, some of the super hard coated seeds need higher temps and longer in my experience. My guess (not based on any specific knowlege or evidence) is that the water hyacynth seed, that simultaneously tolerates environmental temps in the high 30's to low 40's, high humidity and even extended immersion, would probably need a lot more than 45 degrees no matter the period of time in the heap.

The thing about "pasteurization" of compost is that it's not really a pasteurisation designed to kill everything (like in milk), it's a balancing act of killing of the undesirables whilst allowing the beneficials to live. So we get to the grey areas where some weeds are killed and others are not. Also whilst the centre of the heap maybe stable at 55C for 3 days plus, those seeds at the edges live on in a nice warm moist environment. Turning helps, but a static pile is not effective at ensuring a 100% kill rate.

BTW I also make a cold compost that is a great biological inocculator and I plan to use to it as an inocculant in the media based grow beds. It's called cow pat pit or barrel compost and is from the biodynamic stable of preparations and soil improvers.

45 degrees is to break down material properly, to reduce disease and vermin. It's different to PATH or pasteurisation. It's known as VAR Vector Attraction Reduction. Where vectors are disease vectors or rats and stuff.

As for your other comments, I find no argument
Hotter for shorter is acceptable, there's a graph of heat VS time period somewhere, I'll try to find. Generally, we can keep compost at 50 OR 70, sometimes we can't cool it below 90 or 100, but that's composition problems. Despite how we try to control it, the bugs are alive,a nd have lives of their own. They do like to find equilibrium

This plant sounds like something that would be great for a gray water treatment system as well as a fish focused system.

i watched a PBS show on tele a long time ago about Florida's campaign to eradicate these water plants

everything from huge dredges fitted with mechanical choppers to spraying with high pressure steam and even processes as wacky as treating them with arsenic.


i also know the game wardens around here will ticket you if you have any hanging on your boat when leaving any lake or river here. at every boat ramp is a warning sign and i saw a warden write mom and dad a ticket for their big bayliner having some hanging on the ski platform as a hitchiker

i think the plant is still winning the war...

All mine has died, 3 times out of 3! Brown thumb? Brown rot?

Perhaps I should offer my services to the gov't...

"In 1884, Mrs. W.F. Fuller obtained samples of the South American plant, the water hyacinth, at the World’s Industrial and Cotton Centennial Exposition in New Orleans and planted them along the shore of her home on the St. Johns River in Jacksonville. Within a decade, the water hyacinths covered an estimated 50 million acres of the river and its tributaries. Left uncontrolled in North American waters, water hyacinths can cover lakes and ponds, starving them of oxygen and thus killing fish and other organisms."


then the city of Jacksonville names a main bridge after her hubby.