Backyard Aquaponics
A place to discuss aquaponics

what do the esteemed and well informed peoples out there think about growing pyrethrum in an AP system.
I Know that we shouldn't use it with AP because it's supposed to harm the fish but growing it should be ok right as long as you catch the flower heads before they deteriorate.
I have it growing in the ground and it seems to do a good job so far at repelling the nasty critters but now my AP is getting hammered hence the thought of putting it in there too.

Any ideas/alternatives?

What plants are getting hammered and by what bugs? Havn't researched Pyrethrum in grow beds.

my quick research tells me its deadly to insects but I haven't found it being deadly to fish? There are several mentions that it is safe for humans. I wonder if its the case of high/low concentrations, for instance using small concentrations of chloramine to treat water.

I did find a post from another forum that said "all my silvers died from one spray of pyrethrum" but when i clicked on it it said cannot be found Grrrr! You could always grow them in pots around the AP or any dirt areas that arent AP

Should probably be alright... the insecticide is made by firstly drying, then grinding the flowers....

Pyrethrum and its synthetic derivatives (pyrethroids) are toxic to fish. And yes you probably don't want any of the flower parts in the bed.

The fact that pyrethrum plants in your garden are able to repel insects at a distance and thereby protect other nearby plants suggests that there is some biologically active substance wafting around.

Personally I wouldn't be growing it in an AP system.

But since this my first post I am clearly not esteemed nor well-informed.

However, as an entomologist who has grown insects in laboratory cultures and seen them drop dead from what would be considered negligible quantities of chemicals I'm very cautious about these things.

Fair point...

An Entomologst. Charlie, you have competion.

Faye, time to bring out all those photos for identification.

Eskimo. You may not be esteemed or well-informed but there are a few hundred of us who would like your opinion on the various multi legged beasts that keep popping up on this forum.

Welcome.

Thanks Jeff

I'm amazed by the level of knowledge and generosity of the members of this group and would be happy to contribute if I can.

Hi Eskimo did you know that we love photos and we love entomologists too.

We also love beer... and sometimes chocolate

Thanks faye. Should have my system up and running in a couple of weeks. I'll post some pics then.

If there are bio-active things in the air around pyrethrum plants, and if such things are possibly harmful to the fish, wouldn't it be risky to have the plants anywhere close to the AP system - unless maybe it is out in the open. But most seem to be in sheds or courtyards or greenhouses. That would concentrate the possible bio-actives.

Something we used to use a tong tong lime ago when we had gardens as kids was a spray of garlic water. Seemed to stop most nasties from touching the plants. Anybody know if garlic is hazardous to fish? Even if it is, if the plants are not rained on you could still spray it on the leaves etc or perhaps on the boxes, buckets and other gear around the system.

I believe garlic and chili are fine, although I have had limited success with these treatments

I visited a hydroponic grower that had some goldfish in his nutrient tanks for mosquito control. He used an artificial pyrethrum on his plants as a standard with no problems, swapped to natural pyrethrum briefly and all his goldfish died....