Reusing grey water for irrigation

[Than]

I was wondering if anyone here recycles their house's grey water to water their garden and if yes, have they noticed any bad or good effects on plants? Water is quickly becoming a precious metal here so I am considering options. Some online sources say grey water is not good for plants while others say it is fine as long as no chemicals, no borax and no sodium are in it.

[SeanK]

Good Question.

I have wondered about the feasibility of rerouting water from the bathtub drains for watering plants. There were two questions I had:

1. Are palms negatively affected by the soaps that's are used in the shower?

2. Is the shower flow needed to clear toilet waste from the drains down to the septic system?

[floridaPalmMan]

Although its not "gray" water, I use my dehumidifier water as irrigation without any negative effects.

It just serves as another source of irrigation water if its becoming scarce in your area.

[SeanK]

4 hours ago, floridaPalmMan said:

Although its not "gray" water, I use my dehumidifier water as irrigation without any negative effects.

It just serves as another source of irrigation water if its becoming scarce in your area.

I'm pulling a gallon of water every 10 hours from the air in my house with a small dehumidifier.

[Brian]

I have two washing machines that drain to the garden in two separate areas. Several different palm and cycad species get saturated with this water. I’ve been doing this for over 10 years with no negative affects. If you do decide to use gray water in the garden start slowly and watch out for any negative affects on the area. 

[Phoenikakias]

I was using an outdoor shower after sea bath during summer and guess where water was flowing to! Bananas loved it, bromeliads loved it, Guihaia argyrata loved it, Trachy loved it, Wallichia disticha loved it. That's all.

[Than]

12 hours ago, floridaPalmMan said:

Although its not "gray" water, I use my dehumidifier water as irrigation without any negative effects.

It just serves as another source of irrigation water if its becoming scarce in your area.

That would be nice but in our climate summers are dry. 20-30% humidity. So we don't run dehumidifiers. 

[Than]

3 hours ago, Phoenikakias said:

I was using an outdoor shower after sea bath during summer and guess where water was flowing to! Bananas loved it, bromeliads loved it, Guihaia argyrata loved it, Trachy loved it, Wallichia disticha loved it. That's all.

what kind of shampoo or soap do you use there?

[Than]

4 hours ago, Brian said:

I have two washing machines that drain to the garden in two separate areas. Several different palm and cycad species get saturated with this water. I’ve been doing this for over 10 years with no negative affects. If you do decide to use gray water in the garden start slowly and watch out for any negative affects on the area. 

What kind of detergent goes with the grey water?

[Phoenikakias]

55 minutes ago, Than said:

what kind of shampoo or soap do you use there?

Anything, I did not really pay much attention

[happypalms]

I have a bio cycle septic system all my grey water goes into it and it’s the best water you get I put it through a irrigation system (not misting ones health regulations) large droplets only I also worked in nursery once that used there septic and grey water on there large container palms for sale they grew the best also I have an outside laundry with the water going straight onto the ground with a licuala ramsayi absolutely loving it.

[Than]

Wow, looks like plants don't mind chemicals in detergents then.  

Comes as a surprise to me given how often we talk about the minerals in tap water and how we can get rid of them etc but on the other hand water full of detergent (which I guess includes loads of minerals) is OK. @happypalms what is the name of your bio cycle septic system?

I wonder if those detergents are acidic or alkaline... @Phoenikakias have you checked?

I already use bio soap anyway with just 4 ingredients: olive oil, castor oil, almond oil, coconut oil and eucalyptus essence. 

For laundry I use a bio detergent which has borax and soda in it.

 

[Brian]

6 hours ago, Than said:

What kind of detergent goes with the grey water?

 

[Brian]

I think this Arenga is as large as it is due to the laundry water it gets.

 

[Brian]

These plants also get laundry water. Licuala’s love it.

 

[Darold Petty]

A friend of mine diverts the bathroom sink and shower water to his Arenga micrantha.  This palm is the largest and strongest growing example of its kind that I have seen,  truly,  a King Kong of a palm.

[PalmatierMeg]

Cape Coral, FL pioneered a dual water system decades ago. The irrigation system consists of a mixture of recycled wastewater and freshwater canal water. We pay $10 per month for irrigation water and it is a financial boon for us because we don’t have to use potable water to water our gardens. More communities should adopt this system of dual water. Everything in our yard has a much better chance of surviving the late spring hot, dry period of May to mid-June. So, yes, make that “gray water” work for you.

[Tomas]

My doughter when scouting were using biodegradable soaps, for dish washing, showering and shampoo, the soaps were allowed even in protected natural areas.

There are not many minerals in soaps, once there was a lot of phosphorus, but it is over now, you may remember the green water in the Adriatic sea, caused by algae flowering, triggered by the presence of phosphorus.

Btw, a friend of mine collects all his house water (including the black water) in an open collection tank, and there is the water hyacinth growing on the surface, well it is the double size of whatever hyacint I have seen elswhere 

[WaianaeCrider]

Been using shower and laundry water for decades to water my Kukui Nut tree.  Couple of years ago (2019) I planted a Cyrtostachys renda under the tree.  Here's the little guy and the pipe.  Gotta take and up to date photo tomorrow

[Palmarum]

On 6/5/2024 at 10:01 AM, Than said:

I was wondering if anyone here recycles their house's grey water to water their garden and if yes, have they noticed any bad or good effects on plants? ...

I channeled the drain from my washing machine outside and to a small area that includes a few plants, mostly a Cat Palm. The Chamaedorea cataractarum is one of my oldest palms and has since gotten massive on the grey water. It is forming separate colonies. No negative effects after many years, zillion washes and various detergents.

The grey water makes any seedlings that pop up in the area grow extremely fast, so I have to regularly climb into the bushy mess and clean it out. It is so dense, that Veitchia seedlings will germinate and grow in pure Cat Palm leaf bases. 

Ryan

[Than]

14 hours ago, PalmatierMeg said:

Cape Coral, FL pioneered a dual water system decades ago. The irrigation system consists of a mixture of recycled wastewater and freshwater canal water. We pay $10 per month for irrigation water and it is a financial boon for us because we don’t have to use potable water to water our gardens. More communities should adopt this system of dual water. Everything in our yard has a much better chance of surviving the late spring hot, dry period of May to mid-June. So, yes, make that “gray water” work for you.

What is the name of that system?

[Than]

OK you guys have given me immense hope that I won't have to spend half of my earnings on water bills. 

How about palms that like acidic soil? Detergents and soap are very akaline (pH is about 12). Won't grey water negatively affect those?

I will start using the washing machine's grey water to water my Rhapis from now on; it will be my guinea pig and let's see what happens.

[PalmatierMeg]

9 hours ago, Than said:

What is the name of that system?

I’m not sure it has a formal name. Everyone just calls it “dual water”. We have separate pipes and meter boxes for potable and irrigation water. The potable meter box is black, the irrigation box is lavender. The potable water charges vary depending on how much water your house uses. The irrigation system is a flat $10 per month. Except in cases of severe drought we are permitted to run our irrigation 2x per week from 12 a.m. to 4 a.m. Other people water from 4 a.m. to 8 a.m. So, no unlimited irrigation, no irrigation between 8 a.m. and midnight. We were responsible for installing the irrigation lines into 4 zones of our yard. We did not hook up our garden lot to either potable or irrigation so the meter boxes there are unplumbed (saving hook-up fees and monthly charges). I plant drought tolerant palms there and hand water from our original irrigation meter box as needed.

[Motlife]

I haven't tried it personally, but you can buy fertiliser here especially to balance out the nutrient levels in grey water irrigation. Could be worth looking into if a similar thing is available in Greece. 

[rprimbs]

Years ago I set up a grey water system at my moms house in Leucadia.  Her house is at the top of a hill, and has a crawl space under it.  I connected to the shower drains, and the clothes washing machine.  I ran the water out the back in 2 inch ABS,  and down to a plastic barrel I had set in the ground.  The barrel served as a "distribution box", and off of the bottom of the barrel I ran polypipe down to various fruit trees.

The soap, and shampoo did not hurt the trees in the slightest, but when my mom used bleach, with a load of laundry, the small young trees would wilt -- but return to normal later.

[Than]

On 6/8/2024 at 2:59 AM, Motlife said:

I haven't tried it personally, but you can buy fertiliser here especially to balance out the nutrient levels in grey water irrigation. Could be worth looking into if a similar thing is available in Greece. 

that is a great 💡 

[Than]

I am thinking of adding a lemon wedge into the grey water and see how much it lowers the pH. I may add a whole lemon to my big water tank. Another idea is citric acid. Has anyone tried those?

[sonoranfans]

I think it partly depends on the detergents used, phosphate detergents could lead to an accumulation in the soil if it doesnt rain much in your climate.  In florida we already have high phosphate soils but we also have 45-50" of rain a year.  High phosphate levels are known to cause micronutrient deficiencies in Zn and iron if pH is higher than 6.5.    So I guess look for Fe deficiencies and get a soil pH test if you are going to use a lot of gray water.  I would use phosphate free or low phosphate soap if you plan to gray water in a hot dry climate.   I would also balance soil chemistry using humic acid rinses a few times a year just a few days before you fertilize.

for those considering a grey water system:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133124/

 

[Than]

8 minutes ago, sonoranfans said:

I think it partly depends on the detergents used, phosphate detergents could lead to an accumulation in the soil if it doesnt rain much in your climate.  In florida we already have high phosphate soils but we also have 45-50" of rain a year.  High phosphate levels are known to cause micronutrient deficiencies in Zn and iron if pH is higher than 6.5.    So I guess look for Fe deficiencies and get a soil pH test if you are going to use a lot of gray water.  I would use phosphate free or low phosphate soap if you plan to gray water in a hot dry climate.   I would also balance soil chemistry using humic acid rinses a few times a year just a few days before you fertilize.

Great advice, noted

[sonoranfans]

16 minutes ago, Than said:

I am thinking of adding a lemon wedge into the grey water and see how much it lowers the pH. I may add a whole lemon to my big water tank. 

save yourself the trouble, its not going to do anything you can measure.

[Than]

1 minute ago, sonoranfans said:

save yourself the trouble, its not going to do anything you can measure.

perhaps citric acid?

[sonoranfans]

6 minutes ago, Than said:

perhaps citric acid?

just use elemental sulfur pellets in the top 3" of soil and let them get digested by bacteria slowly to sulfate/sulfuric acid(takes months add pmce a year.  No burn risk, slow delivery and sulfur is an essential micro.   I would use 2-3 lbs per plant to give it a good kickstart.  Humicv acid also helps lower soil pH but its not nearly as effective as sulfur in the long run.  In the short run Humic acid is better and I would use it(I do use it myself).  Humic acid also chelates micros making them more available in alkaline soils.  Heavily alkaline soils are another matter, I have no suggestions other than dig it out and replace it.

[Than]

5 hours ago, sonoranfans said:

just use elemental sulfur pellets in the top 3" of soil and let them get digested by bacteria slowly to sulfate/sulfuric acid(takes months add pmce a year.  No burn risk, slow delivery and sulfur is an essential micro.   I would use 2-3 lbs per plant to give it a good kickstart.  Humicv acid also helps lower soil pH but its not nearly as effective as sulfur in the long run.  In the short run Humic acid is better and I would use it(I do use it myself).  Humic acid also chelates micros making them more available in alkaline soils.  Heavily alkaline soils are another matter, I have no suggestions other than dig it out and replace it.

Thanks so much. I'll write everything down on my "plant notes" sheet!

[WaianaeCrider]

On 6/6/2024 at 7:44 PM, WaianaeCrider said:

Been using shower and laundry water for decades to water my Kukui Nut tree.  Couple of years ago (2019) I planted a Cyrtostachys renda under the tree.  Here's the little guy and the pipe.  Gotta take and up to date photo tomorrow

Here is an update.  I guess using gray water is OK.