Greywater... aquatics??

Haven't seen this topic addressed as of yet so I figured I'd do a brain dump of my idea for others to discuss.

Essentially I would like to utilize greywater for small scale aquatics

This would begin with diversion valves in the house so water could be easily redirected back to the existing septic system.

Primary filtration would be coarse media with worms in it to capture the bulk so suspended solids in the effluent.

Secondary filtration would involve a Reed bed, primarily used to grow forage for sheep, to be harvested when the system is winterized every winter and left to grow for entire growing season.

So far pretty normal, no onto the weird part

Third filtration would be an aerated tank used to grow water hyacinth, possibly another species included(such as water lettuce) if it improves filtration.  This tank would have at most a few mosquito fish in it for obvious reasons, or if the water isn't yet suitable for fish than mosquito netting would be a nessacary element.
After that the water would run ti aquaculture tanks for growout if fish/crawdads etc.

Am I way off base in thinking this? From my holey memory the main issues with greywater would be addressed prior to the water entering the aquaculture tanks and the water should be usable by the timenit reaches the tanks

Worth an experiment I suppose, but my suspicion is that even with a reed bed and secondary treatment, you'll have too many surfactants in the water for healthy aquatic life. Definitely need to be EXTREMELY sparing and selective with soaps.

I would be concerned about maintaining the nitrogen cycle and safe pH ranges if you are going to be using soap and shampoo. Going Pooless would help but if you are using a dish detergent even the green products that are marketed as environmentally safe and non toxic might cause issues since this will be a limited closed system.

It you plan to clean dishes and yourself with no other inputs then it likely wouldn't be a huge issue as the introduction of new water will likely have little effect on a system large enough to hold enough fish for aquaculture.
When looking at stocking rates remember that you aren't doing aquaponics unless you are pushing the water housing the fish and crayfish through an additional medium that is heavily planted to take care of the excess waste produced by the stock.

It might be worth it to set up ebb and flow beds to periodically filter and re introduce water cleaning and aererating it.

If you plan to have your stock in a pond it will be harder to harvest efficiently but might be more asthetically pleasing and easier to size in such a way that it requires less intensive inputs for water quality.

Good luck! I hope you come up with a great design and share with us all!

Do you think detergents and the like would tend to push ph lower towards acidity or higher to alkalinity?
I am thinking more sparsely stocked to make it easier to maintain water quality, ebb and flow may be a component but likely only for plants that would do well with low nutrient loads in an aquatics system, more there for filtration than anything, not looking for this system to be full on aquaponics by any means.
I guess I would be happy with it producing water hyacinth more than fish, j7st thinking through the design a bit

I think your idea sounds great!
Based on reports on their use filtering blackwater I suspect that the vermifilter will deal with any chemical issues.
I belive the originator (?) of the vermifilter flush toilet purposefully used conventional amounts and kinds of cleaning chemicals and still got excellent water quality.

Aquatic plants could be an excellent source of biomass for mulch/compost/green manure or as fodder for animals.

I am planning on growing willow in my filter system, with charcoal production as an end goal.
Containing the roots is an added benefit.

I think the fish will be fine but you can always use mosquito dunks if the fish don't survive.

Devon Olsen wrote:Do you think detergents and the like would tend to push ph lower towards acidity or higher to alkalinity?

I believe most detergents and soaps are going to be basic with the more gentle products being closer to neutral. If you are starting with acidic water already then it could even be beneficial but even if you are starting with neutral water you will be diluting the detergents and they will be binding with fatty acids in the oils and grease of your dishes and body funk
So I wouldn't rule it out. That was meant as a suggestion for thought but not to say it is definitely prohibitive.

If the system manages to filter your waste water enough to use on the garden while adding beauty and biomass then it is a win!  I would give it a shot and just measure water parameters to make sure it isn't crazy high or low in anything and if it's not perfect oh well. Cycle it with some mosquito fish and see what happens. I know my fish have always been more resilient in more heavily planted systems.
I want to see how it turns out!

Once again... I find a simple answer for why no one else has brought this up... soap is fish killer, which I should already know from use of mullein seeds to clear fish ponds lol

Still am curious if Reed beds or other natural filters are capable of remov8ng enough soap to make this viable... if n9t greywater to Perennial planting like the rest of the w9rld of smart people lol

Yea soap is a bad guy in aquariums but those are so concentrated I think if you were to use intentionally limited amounts of gentle products it could be possible to use for aquaculture in an IBC set up with a filter media that's planted then a second media planted then floating plants in a several hundred gallon set up or more.

I would be interested to see
1. how heavily one could use conventional bath dish and laundry products and still have viable parameters for aquaculture.

2. If using products marketed as gentle or green made it any easier.

3. If it could be done in an in ground bog and pond based system and support fish without labor and water intensive maintenance.

I'm sure dilution would be helpful

From quick reading before I finish my shift you can remove surfactants through

Electrical current to coagulation the surfactants
Adsorption to remove them via another material
Ultra filtration of the water
High surface area media to increase bacterial colonies that break the surfactants down


It seems Adsorption may be achievable with a carbonaceous material like woodchips or the like
And I have to wonder what a plant like water lettuce would do to b surfactants since it roots so aggressively it will kill fish by clogging gills, so in a separate tank from fish, maybe it would be effective?

What is your goal?

Greywater is fine for watering trees and perennials. Surface systems are very resilient and less smelly than expected, and the soaps and products don't sem to be a problem. I've lived with such systems for almost 30 years here in the high desert. The trees and perennials need irrigation anyway.

I suppose my goal is to utilize the greywater for the most food and fodder production possible prior to letting it out to irrigate Perennial crops(likely hops in the location it will be)
In my head I thought it would be really neat for a portion of that production ti br aquatic crops and fish/shellfish, but it seems leaving fishbout of it is more realistic unless I can devise further methods to remove surfactants