The saying “If it’s yellow, let it mellow; if it’s brown, flush it down” is a well meaning, but controversial guide to preventing unnecessary toilet flushes. Sending less water down the toilet (so to speak) saves money and the environment. But how much could it really save, and is it worth it?
The Good
- Better for the Earth – water conservation and less volume through our sewage treatment plants
- Saves Money – water can be quite expensive in drier parts of the country
- Feels good – not flushing the yellow is a tangible reminder each day that you are doing your part to conserve our natural resources!
The Bad
- Unpleasant odor – a toilet bowl full of urine can get stinky
- Toilet requires cleaning more often – scum build-up seems to occur faster when the toilet is not flushed as often
- Social stigma – this is one of those things you really can only do at home, when you don’t have company
My Experience

Our Flush Savings Tracker (Recreation - original was rendered illegible by a certain three-year-old with a marker!)
Where I live, in Los Angeles, water is scarce. There are many laws governing water use, including how to wash your car, and exactly how many minutes you are allowed to water your lawn (and which days). Because of the scarcity, water can be expensive. We knew this, but were still shocked to get that first water bill after moving from an apartment into a single family home. The water bill was as much as the electric bill for the same period. Yikes!
I immediately changed some things about the way we lived. I adjusted the lawn sprinkler system to the minimum amount of watering time to keep our lawn alive (noting that “alive” is a different place than “green and lush”). I significantly changed the way I wash the dishes and brush my teeth to save water. I taught my children to turn the water off to soap up while washing their hands. And I considered how much money we could save by letting the “yellow mellow”.
I had already stopped flushing at night because the bathroom is right next to the kids bedroom. The walls in this house are paper thin and I didn’t want to risk waking them with a loudly flushing toilet. Over time I just stopped flushing down the yellow during the day, and when my son was potty learning, I never made a big deal about him flushing either. Recently, I decided to figure out how much water and money we could save if the whole family stopped flushing the yellow.
I posted a chart and marker in the bathroom next to the the toilet, and told my husband and son to make a mark every time they didn’t flush. I tracked for a week. The results were fascinating! I saved 5 flushes a day. My three-year-old saved about 7 flushes per day, and scribbled all over my chart so I had trouble counting the tick marks. My husband chose not to participate and recorded only 1 saved flush for the week. My one-year-old learned to flush, and did so whenever she got into the bathroom: an estimated 4 flushes a day wasted. (sigh).
I then did a little research about how much water our toilet holds, and how much water actually costs per gallon. The cost for water here can be tricky to determine. You have to take into account what season it is and what allotment tier you are in (determined by lot size, temperature zone, and number of household members). There are also surcharges for exceeding your allotment, and allotments get reduced during droughts. Water usage is billed per hundred cubic feet. Luckily, my water bill informed we paid $0.005 per gallon for water in Los Angeles (at our house, in March). This is the lowest price we pay during the year. Figuring out how much water we save per flush was easy: the stamp on the inside of our toilet tank says the capacity is 1.6 gallons.
So then, if calculating savings by the flushes saved day (13 – assuming the baby gets over her flushing obsession soon), we are saving 4732 flushes, 7571 gallons of water, and $37.85 per year. If we could get my husband fully on board, our flushes saved per day jumps to 20! (he drinks a lot of tea). That’s a theoretical savings of 7280 flushes, 11648 gallons of water, and $58.24 per year! This is just a little less than we pay for one month of water.*
The other side of this to calculate is the social side. I still flushed at work (2-3x per day), because it’s pretty darn rude to not leave a fresh bowl for the next person in. Can you imagine the office gossip if I stopped flushing? Oy! (Our whole family always flushes when out in public, btw). Also, during the week I was tracking, my husband continued to flush at home every time unless I was standing there insisting he not. I guess he felt the whole idea was a little gross. When he learned that the potential savings was $5 per month for our entire family, he informed me it was NOT worth it to him to stop flushing. I get that. And really, I couldn’t bring myself to ask visitors to our home to participate. I hid the tracking chart when people came over. I even blamed the three year old when we had an unexpected visitor to our bathroom, and I knew the toilet wasn’t flushed.
So does it actually work to “let it mellow”? Is it worth it? I think this is one of those green ideas that is great in the privacy of your own home, but that you don’t really talk about elsewhere. It’s a bit of a green hot topic, perhaps? Choosing to let it mellow can make a difference in water usage, and save you some money long term, depending on the part of the country you live in. But if it’s all too much for your taste, I think you will find few critics.
Have you tried out letting it “mellow”? Would you stop flushing the “yellow” to save $5 a month? Please share your thoughts below!
*I was shocked when I learned what our daily water usage was. Most of it stems from our lawn sprinkler system which runs 3x per week, and for the minimum amount of time needed to keep our lawn alive. (LA does not get much rain, so if you have a lawn, you need to water regularly). We’re in a rental, so there’s not much we can do about re-landscaping for less water use. And we do like having grass for the kids to play in. Still, the conservationist inside me is dying a little bit. I’m so embarrassed.






yay! we let it mellow. I grew up in LA during frequent draughts and we practiced this at home. I don’t think it’s weird at all. Now Dave and I do it at home, unless of course there is company.
Yay Stella! Great to know I have an LA buddy doing the same
I lived in the country (Australia) on tank water for a few years and we lived by the yellow mellow, brown down rule. Everyone in our area lived by that rule, so even the (local) visitors had no qualms about it. I was wondering if you found you did have to clean the toilet more often and if you counted these extra flushes in your calculations?
Although I now live in the suburbs, we don’t flush the toilet through the night (unless it’s brown) and I don’t chase up the children about not flushing after their little wees. Unfortunately, I have to remind them to still flush after a brown deposit!
Hi Carol! I haven’t notied that we have to clean the toilet a LOT more: maybe once a week more frequently? I didn’t include this in the count, but I think it would be a loss of roughly 80 gallons of water and 40 cents pr year.
Clean the toilet, and then pee on top of the cleaning products for awhile…no need to flush at that point. The bowl will still look and smell better after you’ve done some scrubbing. You might flush the toilet BEFORE you start cleaning, but there’s probably already some yellow mellowing at that point!
Thanks for the tip Christine! For a quick clean, I usually just wipe out the visible scum with a baby wipe.
This is interesting. I’m just focusing on trying to get my 5 year old to use less toilet paper for now
I hear you Lisa!
If you’re interested in conserving tp, maybe you would be interested in “family wipes”? I switched our family to cloth wipes in the past and it actually felt better than tp to me. I’ve temporarily switched back to regular tp because of the current hectic state of my life…but I’ve promised myself to go back to cloth wipes again this year!
We let it mellow and clean more often. But Bobo (3) never lets it mellow. If there is mellowing going on, he flushes before he uses. I’m just happy his aim is getting better, so we don’t have to clean the rest of the bathroom as often.
The joy of little boys!
We’ve followed this rule since we moved to the farm. Less flushes = less wear and tear on the well pump and less electricity. Great post.
Thanks Nancy – it’s great to hear that others are doing this as well!
We’re not in a water conservation area, however, I did try this when it was only me and my oldest at home. We did okay, though now with 5 kids, we WANT stuff to flush and not overflow.
If I needed to conserve water, I would definitely try again. Despite what my family said.
Kepp up the good work, busy mama
I have done this in some eras of my life, but we now have a low-flow toilet that becomes very smelly if let mellow even once for a couple hours! So now I do it only if I’ve been drinking so much water that it’s not yellow at all.
How much (or little) water does a low-flush toilet use?
Ours is 1.6 gallons per flush.
Ours is 1.6 gallons as well, but it isn’t labeled as low flush. I wonder how much water a standard flush toliet uses?
At least in the state of Oregon, newer toilets now are only low-flush. the issue is in older homes, or installing a used toilet from an older home.
Just a hint if you’re interested in taking it further. . . I read a post a while back from a family who not only “lets it mellow” but unhooked the drain pipe under their sink and “installed” a bucket to catch the water from brushing teeth, washing hands, etc, and used that water to flush the toilet.
What an interesting idea! I will definitely try it in a few years. (Right now, with little ones around, I feel like an open bucket of water is just asking for trouble!)
My aunt and uncle used to do this until one day a lady and her little boy arrived to visit. The little boy refused to enter the house shouting, ‘I don’t want to go in there. Their house smells like pee!’ They flush every time now. I abhor the smell of an unflushed toilet. We do live where water is still plentiful and we have our own well so we don’t have a water bill but we do try not to just waste water.
Funny story! I draw the line at odor. If I can smell the bowl, I flush.
I just posted on my blog 15 easy ways to go green (and save money), but this did not make the list. It just grosses me out, so I can’t bring myself to do it.
My grandparents always had this rule in their house though, so I don’t think it’s weird or anything, just not for us
Yes, there definitely is a gross factor to get over. I guess after having kids, a little bit of pee doesn’r really bother me.
Your story is a hoot. We do this at night too. (Glad we’re not the only ones.) After your story though, I decided it was probably not worth it. I decided this because of all the extra efforts and cleaning products (green products) to clean that nasty toilet more often than when we do flush. Products cost money and so does my time, darn it! I could “spend” my time on better things…you know, like LAUNDRY, or DISHES, or COOKING, or ETC., ETC., ETC. Ha!
Thought I’d make YOU laugh since you made me.
Take care!
You crack me up, April! Thanks for reading
get a gooseneck bottle and use straight white vinegar under the rim after each flush. I re-purposed my bottle from a friend who still buys “commercial toilet cleaning products”. The vinegar will reduce both the smell and the “scum” buildup from the “mellow” process. We are on a spring-tank so I limit flushes and reduce gallons with a water-filled 1/2 gal. milk jug in the tank. I tried a gallon jug, but the tank only holds 1.6 gal, so the “brown” was NOT going down. Also, paper only goes in toilet if it is “brown”. “Yellow” paper goes in trash which is composted for garden mulch. My next step is to make “Tidy Wipes” out of old flannel nighties. Toss in wash with laundry + even more reduction of waste in septic. The guys are not too interested in the Tidy Wipe idea, but there are 3 ladies here, we use the most of the paper anyway.
I keep hearing that guys are not interested in cloth wipes (my guy included). Why is that?
As far as I can tell, the issue is the “gross” factor. They don’t need the wipes for the “yellow” like us girls do, and they don’t like the idea of “skidmarks” being saved up for the laundry cycle.
So funny, i always yell at my son, because he forgets to flush, you know you can put a filled water bottle into the tank to reduce the water you use to flush, or if laws permit it collect rainwater not only to water the plants, and flush the toilet. My sons 4 and 2 have a great way on saving water, as the just use their “Bush” toilet during the day lol
Adding a filled water bottle is a great idea. Thanks Martina!
We are on tank water, so it seems like a total waste to flush unless absolutely necessary. We probably only flush a couple of times a day. The downside, as you say, is the smell in summer can get a bit strong (We do flush more often in summer), and remembering to flush before visitors turn up! And remembering to flush when using toilets at work or in public places, as I get so used to not flushing. My husband prefers to wee outside (we are on 8 acres, so no neighbours close by), so he’s no trouble (the challenge is trying to persuade him to wee on my lemon tree though!). We also don’t worry too much about cleaning the toilet, especially as we have a septic system, so have to be careful what/how much chemicals we use. Since being on tank water, our water use habits have really changed, we consider every drop, and think twice about whether things really need to be washed. All the greywater goes on our garden. Anyway, I think its great that you brought up the idea and got more people thinking about it.
With a limited supply, I can understand why you would consider every drop. It’s too bad we all don’t remember that we are on a limited supply!
Recently I came upon a situation that prompted another line.
If its yellow, let it mellow.
If its brown, flush it down.
If its red, use your head.
Thanks for sharing your wisdom with us, John!
We keep a bucket in the shower recess to catch the water that is usually wasted while the water heats up to temperature. This then gets used on the garden, or if we have had a lot of rain, into the washing machine. Washing machine water is diverted with a long hose pipe to run onto the grass (make sure you use a phosphate free detergent). We have a dual flush toilet that uses minimal water for the yellow, so I feel ok that personally the mellow is a bridge too far for me.
It sounds like you are doing a great job of water conservation, Louise. I’m going to try to figure out the washing machine water diversion – what a great idea!
You can also flush the toilet by pouring shower-water directly from the bucket into the toilet. The trick is using a bucket with a spout and pouring it into the hole in the toilet bowl. You’ll get the hang of it. We can also use the shower water for mopping. Then I use it to water my flowers and shrubs and trees (but not edible plants). I don’t like to use mop water in the toilet because it’s just as rank as pee (if not worse…)
I also tried the “let it mellow’ method. I found a good alternative that saves water and doesn’t gross out your visitors. I did get some grossed out looks when i would ask my sister in law and my husband’s friends to not flush. And I too blamed it on my baby saying it would wake her up because of the super thin walls. The tank on my toilet was holding way more water than what needed to be flushed with. I put a 2 liter filled with a little sand inside of my tank so that the water would fill up to level without using so much water! Some people use other things such as bricks in their tanks. I still let it mellow at night but don’t ask the kids to. My nieces like to leave not just their pee in there so I like to get them in the habit of always flushing. =)
Elisa, you’re brave to ask guests to let it mellow too! I’ve only recently learned about putting something else in the tank to decrease the flush capacity. What a great idea!
My husband and I do this. I take it a step further (don’t read beyond here if the “mellow” grosses you out…)
So, I don’t use TP unless I’ve had a bowel movement. What do I use instead? I use small rags, made of old T-shirts. Hear me out, though. Cloth diapers are a thing, why is it bad then to use cloth wipes? After I wipe, I just drop it into a bucket of sanitizer and deal with it when I do laundry. You can also rinse the cloths out when you wash your hands, but that seems like more of a water waste to me, YMMV. I do empty and hide the bucket when we have guests, though, because I know it grosses people out for some reason. I’ve found that the cloth is so much nicer on my lady bits, and it saves us a ton in TP costs.
Family Cloth! Yes, this is on my list to try, although I don’t think it would save a ton of paper right now. It seems boys don’t feel the need to wipe anything after peeing, and my daughter is still in diapers. I’m with you though, I don’t think I’m set up well logistically to use family cloth for BMs. Also, my husband almost put me on the train to crazy town when I floated the idea
Hah! Mine thinks I’m insane, too! We just got our electric bill, our water bill is on the way (I’m scared), and everything costs so much more down here. See, we just moved from FL, and when your average utilities goes from $100 to almost $400, the wife seems a little less crazy when it comes to saving money where ever she can.
Or, at least I like to think that’s the case. Besides, he can think I’m crazy all he wants, it’s not like he can send me anywhere, I’m the one that cooks. hehe
I have adressed the waste issue to guests by saying “having septic tank issues…please do not flush unless solid waste. Liquid waste can set for a while. Ladies, please only flush ‘dirty’ TP, damp can go in the trash” Some of my “younger guests” are grossed out, but the older generation seems to understand.
for personal use, I am finding the cloth is working well. I only use the traditional TP when solid waste needs
I applaud you for talking honestly about a subject many find taboo! Waste is a normal, natural part of everyday life and we should not be so embarrassed or grossed out to talk about something everybody does!
I do this, but I only ‘let it mellow’ once, i.e. I flush every two times I pee. With my style, I only have to clean the bathroom twice a month. (wWe’re two people in this house; I live with my husband.) It’s about saving time, not just about saving water or money!
Of course, when it’s ‘brown’ – or red! – I flush immediately. Talking about ‘red,’ I’m all for menstrual cups and rewashable sanitary napkins.
I work in the evenings, so at night I’m too tired to wash the dishes. (I don’t have a dishwasher.) I always put dishwashing liquid on the dishes, removing all food particles, early in the morning before my shower. Then, I place the dishes on the dishrack, which I place in the shower. I need five seconds to wait for the water to get warm: that (and a little bit more) is enough water to rinse my dishes.
When my husband takes a shower, he collects the extra water in a bucket. It fills up to about half its volume. I use that water to flush the toilet… which brings me back to my first paragraph!
Good post! Nice to talk to likeminded people!
Great article and great important discussion!
To me, it is not about the dollar value, though I do appreciate the savings, even $5 a month. It is about this precious, dwindling resource of clean water.
We can decide to lead in this area, and eduacate our friends, neighbours, guest and co-workers about it rather that hiding our practices as if it was shameful. We have been brainwashed by our modern society to be ashamed of our bodily functions, but actually everyone urinates (if they are well and are to stay alive), and this is the way it has been since God – or evolutions – put us on this planet.
If we want our children, and their children, to be able to survive on this earh, we will have to push ourselves to be that bold in many areas, so we might as well start here!
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A number of years ago, I lived at a place where we had to haul every drop of water we used. Not only did we use the let it mellow, we put a shut off on the shower so that we could get wet, reach up and turn off the water (thus keeping the temp adjustment) and soap up and then turn the water back on to rinse. Washer was used for full loads. Dishwasher when used was FULL. Currently, we have a slow well. Sometimes we have water. Sometimes we can’t even take a shower due to low water level in the tank and the livestock come first. You do what you need to do!
In 1991 I bought 20 acres of land with no improvements. I has sold my home, so this meant moving onto the land with 3 registered Appy mares, a dog and a husband (who was just about useless) All water had to be hauled, so I learned to ration and re-use where ever possible. We built a barn first, and moved my wood cook stove in. Now I had heat, cooking, and dishwashing facilities. Two old fashioned metal dishpans were my wash and rinse. Wash was with yesterdays rinse water, wash water became garden water. Garden was container-grown to conserve water. I can still brush my teeth and wash my face with 1 cup of water. Three years later, when I finally was able to sink a shallow (90 ft.) well we only came up with 1/2 gal. per min, so I set up a holding tank and shut-off system. we had plenty of water for the horses and a real garden, but I still hoarded my water like liquid gold. Finally after 4 years of drunken rages and verbal abuse the husband put me in the hospital with a split skull and concussion. He left, and my family stepped up to help deepen the well and get me a mobile to live in. Now at 225 feet, I have 25 gal. per minuite, but I still conserve water. I still wash full loads of laundry and dishes, shut the water off while brushing my teeth, and let it mellow!
MNI WICOZANI – Water is life
Another trick I like to use is to put a soda bottle of water (or a brick, anything solid) inside the cistern. So long as you position it so that it doesn’t interfere with any of the internal mechanics, you save that volume of water with every flush. It is a good way to minimize your water usage without any daily effort or gross factor.
I found your discussion because we had recently started the “if it’s yellow let it mellow” idea in our home because our city has the highest water bills anywhere. We have a family of 3 and our combined water sewer bill which comes every other month is easily about $360 this is not due to water shortages or anything like that. We live in NW Washington state and the other cities around us have much much lower rates! At this rate even $5 a month will help. I appreciate all the comments people left with suggestions. I noticed a few people mentioned the water jug in the back of the toilet, another idea is to just place a brick or two in there. I will also often turn off the shower while I am washing or shaving. Or my husband and I just shower together so while one rinses the other is washing this also gives us the opportunity to talk about our day or whatever with out kids bugging us about stuff.
The shower idea is great…but it would not work with my hubby…We would end up using MUCH MORE water than 2 individual showers…LOL
LOL!! Yeah that has been a problem a time or two, but usually we manage to keep to the task at hand.
Dea – you stole the witty comment right out of my mouth!
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My family (we live in Hong Kong) has been following the “If it’s yellow let it mellow, if it’s brown flush it down” mantra for a few years now, so I totally buy it. However recently I’ve noticed that the toilet bowls are really stained and our normal practice of using store bought toilet bowl cleaner just does not crack it. While I don’t mind it so much, it’s just not very esthetic to look at. Any ideas how to clean up stained toilet bowls?