Question: “I want to change my substrate, how?” OR “I want a whole tank overhaul, how?”

The first, most important question that begs asking is “Do you usually do 50% weekly water changes?” If yes, please continue with the article. If not, stop right here, go read about “Old Tank Syndrome” and how to deal with that first. If you do not already have fish accustomed to large water changes, trying the article below can and will cause osmotic shock, and kill your fish.

Usually, if you keep up with weekly 50% tank cleanings with gravel vacs and more thorough monthly or so “deep” cleanings, this kind of “take your tank apart and scrub everything” type of cleaning isn’t necessary, and it is a little dangerous. However, if you want to change out your gravel, or want a whole new “look” then that is a better excuse to rip it all up like this.

Some alternatives to regular aquarium gravel.




Eco Complete


Please note: it’s very important to keep your filter media wet.

  • Here is the plan:Now you want to work as quickly as you can, so you want to have everything thought out and gathered together before you start. Have your new gravel rinsed and ready first, for example.You’ll need several buckets or plastic containers of some sort that have never been used for anything except fish. They need to have never had any type of cleaner of chemical in them. One of them can be an ice chest. Large Tupperware type containers work also. For this article, I’m going with an ice chest because it will help keep your fish at a steady temperature.A water changer is very, very helpful with this whole process, and the article assumes you are using one.

    Drain some tank water into the ice chest, and place fish in the ice chest.

    Turn off all filters and heaters.

    Drain some tank water into a bucket. Use this bucket to clean your filter media, such as your bio wheel (if you have one, or floss, whatever non-replaceable media you have). Just swish it around in there. Then, put the bio wheel (or floss) in the ice chest water with the fish. Close the ice chest and put it somewhere out of the way where the temperature won’t change much. Like, not outside or in the garage.

    Pour out the tank water you swished the bio wheel in. Pour more tank water in the bucket and clean the rest of your filter media in it, like the blue pads or what have you. Swish them around to clean them as best you can. If they are wearing out and need replaced, don’t worry about this step so much, but, keep these pads wet for now too. Do you have real plants? If so, carefully remove them, and put them in the bucket too, they’ll need to stay warm and wet. Set that bucket aside.

    Drain the rest of the water outside, or down the drain, while vacuuming the gravel. You are going to get this gravel out, but you might as well have it as clean as possible now, to save you work later.

    Remove all your decorations. You can clean these in tap water, because you are protecting your bio-colony in your filter media you have in the ice chest. Clean your filter casings now too. (The casings, not the media!)

    If you are going to keep the gravel to use in another tank someday, you’ll want to remove the gravel and put it in another bucket or buckets. Set it aside for now.

    Now, your tank is empty, right? Take it outside with your algae scrubber. Use the hose and the scrubber to clean it up. Or, if it’s cold out, you might be able to use the bathtub if the tank is not too large. Be careful, it’ll break if you hit it on the side of the tub. Outside is better, but if it’s a large tank, clean it right where it is. Scrub that sucker clean. Take it back in the house. Put the new, already clean and rinsed gravel in. Put your newly cleaned decorations back in. Put the dechlorinator, such as Prime, in and a couple inches of water. Next, put your plants back in. Do all your aquascaping now.

    Fill the tank back up slowly and gently so you don’t raise too much dust. Make sure the water is the proper temperature coming out of the tap. Make sure the heater is in place and plugged in, after the water level is high enough. Put the newly cleaned filter back together and get it running. (If you are replacing media like blue pads, try to keep some of the old media to add in there. Even though you have the bio-wheel or floss, since you are doing a major overhaul, the extra help is a good idea.) It should clear the tank out pretty fast.

    Acclimate your fish to the new tank like you would if they were new from the store, because it’s all new water to them.

    Sit back and enjoy all your hard work.

    Remember to clean your old gravel, if you are saving it, and put it somewhere that it will dry completely. Then, after it’s dry, you’ll need to think of a way to store it. Just don’t store it wet or dirty, you’ll regret it when you try to use it again some day. If you put it away dirty or wet, it can get really gross with methane, hydrogen sulfide … think “swamp” here.

    For example, I was once given a tank that belonged to a man who had died two years previously. His tank was broken down and stored by non-fish people. It was stored for two years, and then the whole thing was given to me. The substrate was just plain gravel … natural pebbles … and it had been stored in zip top bags, wet and dirty. Two years later when I opened those bags, it was a smelly, gross, slimy, moldy mess. I’m a stubborn wench, and I did get it all clean and reuse it, it’s still in the tank to this day, but opening those bags is one of my most unpleasant fish keeping memories!

    It was actually easy to clean, but smelly and time consuming. I just put it in buckets and kept rinsing it with fresh water, and airing it out in the sun on flat trays. The repeated cleaning and airing (hot summer sun) cleaned it up well!

    Of course, this happened long, long ago, when I was just a fish keeping noob myself. I had no idea then how cheap it would have been just to replace it. An even cheaper solution though is cleaning it up and storing it properly in the first place, to reuse at a later time.

    I want to change my substrate, how? By: Texasdawn


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