The Green Pee Cat Litter System




Introduction: The Green Pee Cat Litter System

The Green Pee Cat Litter System uses a non-porous filler, pea gravel in a perforated tray sitting in a second tray that contains an absorbent layer of newspaper with baking soda.
The cat urine flows through the non-porous pea gravel into the second tray where it is absorbed by the news and the odors are neutralized by the baking soda.

All you have to do is scoop out the solids from the pea gravel once a day and change out the newspaper and baking soda once a week.
Once a month or so you change out the gravel. The gravel is hosed off or dumped outside where the rain cleans it and it can be reused.

My cats had to be trained to go on the gravel.
I put regular cat litter on one side of the box and pea gravel on the other side.
There was some mixing of the two as the cat used the box.
Then I gradually used less litter and more gravel.
Now my cats use the new system with only pea gravel and my life is a little easier

Green Pee Cat Litter System is green because it:
1- Stops all the cat litter going into the landfills.
2- Saves the cost of buying cat litter.
3- Recycles newspaper.
4- Saves time changing out cat box.
5- Helps control odor.

Step 1: Drill Holes in One Tray

Holes are drilled in one tray

Step 2: Newspaper and Baking Soda Are Put in the Bottom Tray

Newspaper and baking soda are put in the bottom tray

Step 3: The Trays Are Combined

The trays are combined

Step 4: The Cats Are Trained

The cats are trained by using pea gravel on one side and cat litter on the other

Step 5: The Gravel and Litter Mix As the Cat Use the Box.

The gravel and litter mix as the cat use the box.

Step 6: Eventually You Can Use Only Gravel.

Eventually you can use only gravel.

Step 7: Separate the Trays to Clean the Bottom Section

Separate the trays to clean the bottom section

Step 8: Dump the Newspaper and Install New Paper and Baking Soda

Dump the newspaper and install new paper and baking soda

Step 9: The Gravel Is Dumped Once a Month or So in an Area That It Can Be Washed and Reused

The gravel is dumped once a month or so in an area that it can be washed and reused



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    66 Discussions

    I will try this. I may use aquarium gravel instead. I think it is small enough and soft enough that the cats won't mind stepping in it as much. I cannot imagine how bad the upper tray must stink. After working 10 hours a day I am pretty sure the house is going to reak of cat poop. We will see.

    Okay, you said: "Stops all the cat litter going into the landfills." What's the problem with cat litter going into landfills? Cat litter is organic. It's either made of clay or wood. It decomposes perfectly fine in landfills. Besides, if you're worried about putting stuff in landfills that don't decompose, then why does your picture show the dirty newspaper sitting inside a "PLASTIC" bag? The plastic bags you use will end up in the landfill. .............. Also, I wouldn't us the gravel because cat poop can be sticky or runny and you can't just pick that up off of the gravel and expect the gravel to be clean. There will be fecal matter still on the gravel for your cat to step on and transfer it to its feet, then the cat gets out of the pan and gets on your furniture, or on the carpet (which if you have a crawling baby on the floor, the baby is touching that cat feces and then putting its hands in it mouth), or your cat gets on your lap. YUCK! No thank you, I don't want cat feces all over my house. Sorry, I'll stick to the clumping litter that is much more sanitary.

    1 reply

    Clay is an inert material, but it also takes up land-fill space. The more material we throw into land-fills, the more land we have to clear and convert to land-fill. We certainly aren't at the theoretical re-mine/re-use part of the land-fill lifespan yet. (Unless you count land-fill methane extraction).
    Clay litters can also cause silicosis (think asbestosis). Those clays that use bentonite can also cause intestinal distress, as the dust can stick to kitty feet and bottoms, and is ingested when the cat grooms.
    Wood litters are biodegradable, but you have to ensure that your supplier produces them from renewably managed forests or plantations. Recycled paper pellets are a better option, but don't have the deodorising abilities of wood pellets. The bicarbonate is a good solution for this but is irritating (It's basic, pH about 9) if the cat comes in direct skin contact with it. Again, they also take up land-fill space if not composted, and this has big environmental impacts despite being biodegradable.
    I'd love if a system like this could have the bottom tray plumbed in, and the pee flushed out into a black-water line once the cat stepped out of the tray. Add a fan to draw smells down from the top tray (and dry the poop a bit) and you've got something really cool.

    This could work especially well for cats fed a raw/meat-based diet. The poo will be smaller and drier, so not very smelly and won't stick much to the gravel.

    Great, thanks for the instructable! I can honestly say this has changed my life. No more sweeping up tracked litter several times a day.

    I used a pair of tall clear 57l plastic containers (the high sides contain everything but can still be seen through so my cats will actually use it!) and cut an entrance in
    one end. The two boxes have lugs so when stacked they leave about 1" for the wee collection. My cats aren't very keen on pebbles under their paws so I used baked clay balls (the ones used for hydroponics). My older cat was straight in it, surprisingly no need for any transition from clumping litter to the clay balls! And there is no more tracking round the house, just a couple of clay balls to pick up if he's been a bit enthusiastic with his digging.

    They are a bit dusty straight out of the bag so I give them a good rinse in a collander before tipping into the tray, to stop muddy footprints round the house.

    The clay balls have become a little bit whiffy so I'm going to try soaking a batch in diluted vinegar, and will leave another batch outside.


    1 year ago

    if I lightly dust the clean dry pea stones with Cornstarch, would it reduce rather amount stones sticking to the poo when it's time to scoop? And vice versa...

    I've been using this system (ok, my cat, not me) for several months, and it seems to be working really well! I like the idea of putting water in the bottom tray. Lemon juice is a good odor neutralizer, but I've heard that cats detest citrus. Maybe a few sprigs of fresh lavender or drops of oil in the water? I have rotating batches of gravel so that it can be properly rinsed and aired out over time. I also soak in vinegar if the odor is especially potent, but you have to be sure it doesn't smell like vinegar when reusing it, or the cat may decide that's not the place to go, anymore. If you use a towel instead of newspaper, you can rinse it, then soak in vinegar prior to washing. It works as a fabric softener, too! Thanks for sharing a fantastic idea!

    5 replies

    Maybe tea tree oil? I have a Hamilton Beach 04271R TrueAir Plug-Mount Odor Eliminator near my litter box. I use an extension cord, and put it on top of the litter box hood. The stinky air gets pulled through a carbon filter before getting back into the rest of the room.

    FYI: tea tree oil is a not use it on or near kitty's habitat

    I know this is a year later, but, the best item I've found for getting rid of pet odor is Yard Odor Killer   stool &urine deodorizer made by Garmon Corp.  1-888-628-8783 

    I know this post is old, but I had to post a reply. You should never use essential oils around cats, or at the very least you should be very cautious and prudent as to their usage. Cats cannot metabolize them in the same way humans or even dogs can, and most essential oils (especially in the amounts we humans with our weak noses use) can make cats very sick, especially if they make contact with cat's skin.

    Oh, also, I'm a big fan of putting baking powder at the bottom of litter boxes. It neutralizes the urine.

    Hi, we're looking to try this as we've recently become short of money... But... We can't really afford baking soda, is there anything else cheaper to use?

    3 replies

    Google around, you can buy it in huge bags for cleaning purposes, it's much cheaper. $7 for a few kg.

    Baking soda is just about the cheapest thing you can buy. Less than $1 for a 2x4x5inch box in any grocery store.

    I read lately in to use wood pellets, seems to be at least half the price of regular litter. I too was amazed how the rain spout washed the pea gravel, thanks!

    Okay, that's clever. Good instructable, great photos and step-by-steps. Nice work.

    Okay, that's clever. Good instructable, great photos and step-by-steps. Nice work.

    You can purchase a box system that is designed to use saflower seeds, i think. its three parts: slotted tray with seeds on top, bottom slopped tray to catch urine and a very small plastic box that hold the urine and slides into the bottom tray.

    I hooked a hose to the funnel of the the bottom tray and attached the other end to the down drain to sewer. Very easy to do.

    I also put one in a bedroom, but have it draining outside to a gallon jug with holes to the flower bed. I add water to dillute the urine.

    You can buy plastic pellets to use instead of the seeds.. its cleaner than the seeds, and less expensive, and faily easy to clean. I was them with vinegar.

    Also, you can just put the setup on plastic stand, drill a hole in the top of the shelf and funel/tube it to a one gallon jar with about an inch of vinegar in it. Works great. This is how i did it for testing. Do not pour this on anything you want to live outside, the vinegar kills it.

    OH YES; forgot to mention; that when I scoop the solids I do use newspaper (cut a full sheet by 1/4 & keep large stack in bin close by). Newspaper does keep any smell from escaping. DO NOT FLUSH CAT SOLIDS!!! If you're not sure why; google it!!