Terrible Advice Tuesday (T.A.Tues): Blame the Cat…?

Your cat’s litter box should not be located near your saltwater tank as the ammonia from the litter box (caused by the cat urinating) will get into your tank and raise ammonia levels.

The rest of the story: While your cat might try to eat your fish by catching them, don’t blame Fluffy for elevated ammonia levels in your tank.

Here’s why:

For a cat’s litter box to elevate ammonia levels in your tank, the litter box would  have to give off LOTS of ammonia.  So much so that you would likely be affected long before your tank. You’d probably have difficulty breathing and your eyes would be burning if you got anywhere close to the ammonia-laden room.

If ammonia levels were this high for an extended period of time, then I might be concerned about rising ammonia levels in your tank.  However, if the ammonia levels got anywhere close to a high level, you’d probably notice it and empty the cat’s litter box or at least move it outside.

Also, most cat litter products have an odor (i.e. ammonia) trapping component in them. Therefore any ammonia escaping would be minimal.

My advice: Keep the cat and don’t worry about the litter box being next to your tank. Or why not find the cat a new home…the litter box is taking up space where you could put another (or a bigger) tank!

Special thanks to Brandon R. from my Facebook page for his suggestion for this T.A.Tues.

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Comments for this article (17)

  • Zeek says:

    Thanks Mark!

    I have 2 cats and one large litter box and I have never had any problems(or it hadn’t occurred to me to blame it on that).

    One other concern I have had however is cat hair. I try to brush them and keep the house clean but let’s face it I have fans pulling air into my canopy and I see some get caught in the filter socks from time to time.

    Again never really worried about it but pondered it lightly..


  • Angel says:


  • Zeek…if the cat hair clogs the fans pulling in air to your canopy, then I’d clean the fans. I wouldn’t worry about cat hair getting into your filter socks. Just clean the socks and remove the hair.

  • William says:

    I’m getting rid of the cat and getting a bigger tank!

  • chris purvis says:

    That helps! I’m building out a fish tank room right now and was concerned more about the dust that gets in the air when pouring new material into the litter box. (on the other hand was really trying to tell the wife I need to get rid of the cat because of the tank).

  • Rhonda Riebow says:

    No, don’t get rid of the kitties! Once in a while I get long collie hairs in my tank. Sometimes before I can fish them out my Royal Gramma grabs them and tucks them in his cave.

  • Jimbo says:

    these comments are so frickin dumb do ppl. really believe this? man some ppl. are very dumb!

  • Kevin O. says:

    Why would you want a nasty litter box next to your beautiful tank?

  • Kevin C. says:

    Better to keep the box away from the tank anyway. The dust kicked up from the cat scratching around could drift to the tank. Probably wouldn’t harm anything but still.

  • melody says:

    Well I don’t have a cat, but have a dog who sheds terribly and I have wondered about the hairs I see in the tank, does that affect anything? I try to fish them out when I can get to them. I worry about that & was so suprised to see the comment about dog hair.

  • Patrick says:

    Jimbo, if you think its so dumb just simply don’t read it. or go read something somewhere else!!

  • Rick Schmidt says:

    I have two cats. Not sure which I like watching more; the tank, or the cat’s watching the tank. The fish have grown accustomed to them watching, and now go to the glass just to infuriate the cats. The cats are just not as smart as the fish, since the fish know the cats can’t get to them, but the cats keep trying. They usually chase a fish until they fall off the two stools set in front of the tank. The gobie is the most fun to watch, since he will gobble sand in front of them, then shoot off to one side or the other of the tank, and the cats run right after him with no regard of the surface underneath them. They normally run after him until the run right off the stools. Quite funny to watch, the gobie laughs just as much as I do.

  • Peter says:

    No litter box more tanks!….I like that idea 🙂

  • Diver says:

    Jimbo if you could read correctly… Mark was stating DON’T believe the rumour that the cats box is adding ammonia to your tank. Take a chill pill buddy ’cause posting rediculous statements makes you look…. well, rediculous!

  • John B says:

    LOL really would have never crossed my mind to blame a litter box. What does worry me from time to time is I use Frontline flea and tick on my dog. After using it I am always extra careful not to pet my dog and then do anything with tank maintenance, feeding or anything tank related for fear of the Frontline effecting fish or inverts in my tank. I am guessing what kills fleas and ticks might not be good for my tank inhabitants. I always wash my hands after petting my dog.

  • JasPR says:

    Interesting subject. We hobbyists tend to think of three nitrogen species- Inorganic ammonia
    But thats way too tidey for a living system like the ones we maintain. Instead we many intermediate species also gaseous forms.
    I’ve been to wholesaler facilities and koi shows and you can ‘smell’ the ammonia leaving the water– it is a quite recognizable and familiar odor!
    The gas venting from your cat box urine is only one of the reasons why cats with their sensitive noses won’t pee in the box at a certain point! I doubt the venturi effect from concentration of ammonia gases in the air can move the neddle or color kit a fraction if at all. Instead, your towers and sumps are degassing a percentage of ammonia themselves as the water evaporates. Here’s a thought– the use of metal halides is getting a bad rap lately due to heat and energy consumption. But that evaporation you hate also removes the gaseous form of ammonia in the process- small but helpful

  • nevillekilcc says:

    A great video to help many people, old or new to the hobby, would be an explanation of voltage in the aquarium water! Even a new system will carry anywhere from 4 to 60 Volts! Thats insane. There is so much speculation around the subject that i would find it to be very clarifying 🙂

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