IV. EMERGENCY: How to Quickly Cycle a New Tank

Help Me!
“Help me! I recently set up a fish tank and just bought a new puffer (or other fish), but now it’s dying on me!”

Did you just set up a tank within the last 2 months, went to the store and purchased a puffer (or another fish), brought them home, and now they are looking like they are dying?  If so, you are probably suffering from an uncycled tank.

You need to take action IMMEDIATE or you puffer/fish will be dead before the day is over!

Note To Reader: Read this entire article from start to finish! It will take 10 to 20 minutes to read, but it could SAVE YOUR FISH if your tank is new!

What is happening?
Here is a quick overview of what is happening in your tank.  In simple terms, the pee and poop of your fish is poisoning and killing them!

The waste produced by your fish creates a chemical called Ammonia (among other chemicals), which is VERY poisonous to fish (though some tolerate it more than others).  Ammonia actually burns the skin of fish!  In order to remove the toxicity (poisonousness) of Ammonia, you need several types of beneficial bacteria to consume the chemical.  This build-up of bacteria is what we call a cycled tank.  Tanks that have had fish in them for less than 2 months are typically considered to be uncycled, as they do not have this build up of bacteria.

What options do I have?
You need to remove these toxins AS SOON AS POSSIBLE!  There are several options you can choose from:

  1. Get some used filter media or sponges from a HEALTHY TANK (very important) and add them to your existing filter(s)
  2. Purchase and use BioSpira or Dr. Tim’s (use with caution)
  3. Purchase and use Prime dechlorinator in combination with water changes
  4. Perform massive water changes (around 50 – 100% water changes every day)

What do I do?
We need to test the water to see what toxins are already in the tank.  Some stores will do this for you for a small fee (or sometimes free).  If you can’t afford the test kits right now, ask your local fish store to test your water.  Make sure you ask for numerical readings for every test!  Many will give you a “it’s fine” answer, which won’t be sufficient at this time.

If you can purchase the test kits, follow these instructions:

  1. First, you need to purchase two test kits:  Ammonia test kit, and Nitrite test kit.  Make sure they are for the type of water you have (ie. Freshwater test kits for a Freshwater tank) and that they are the LIQUID test kit and not the test strips (which are mostly inaccurate).
  2. Test your water with both test kits (follow their instructions).
  3. If you have no reading (a reading of 0 ppm) of Ammonia or Nitrite, then keep testing your water every 2 hours for the next couple of days.
  4. If you have a reading of Ammonia and/or Nitrite, please continue reading.

Your first problem is that you need to remove the toxins (such as Ammonia and Nitrite) from your water.  This is done by introducing the beneficial bacteria (mentioned earlier) into your tank, which consume these toxins.  There are several ways to get this bacteria:

Used Filter Media or Sponges
Used sponges/media contain some of the bacteria you need to remove the toxins and will quickly help to solve your problem!

If you already have other fish tanks (or know a friend who has tanks) of the same water-type (which are Freshwater, Brackish, and Saltwater) as your current tank, the tank is HEALTHY (ie. no diseased or dying fish), and that tank currently has fish in it and has had fish in it for more than 2 months, simply remove one of the sponges or bags of media from it’s filter and add it to your tank’s filter.  If this is from a tank not located in your home, you need to transport the sponge/media submerged in water from its tank!  If you do not keep the sponge/media under water, the bacteria will die very quickly.  Also, if you are transporting the sponge/media from somewhere, you cannot leave it in the bag for longer than 2 hours, as this will also kill the bacteria.

If you do not know anyone who has fish tanks, you might try going back to your fish store and ask them if they have some USED sponges you could have/buy (they MUST be from a HEALTHY tank that has fish in it and the sponges must have been used for at least 2 weeks).  If they try to sell you new sponges or some other product, simply leave, as only the products I mention below have worked properly.  Some stores will try to sell you Ammonia-removing products, which you MUST NOT BUY!  These products prevent the tank from properly cycling, which will leave you crippled and in the same troublesome position in the near-future.  Remember, we’re trying to solve the problem, not just slapping a band-aid on it.

BioSpira and Dr. Tim’s – (USE WITH CAUTION)
** Not available in every country.

CAUTION:  Many stores have a terrible habit of improperly storing these products.  If you buy these, make sure you check how it is stored (BioSpira must be refrigerated, Dr. Tim’s does not need to be) and the expiration date.  There is also a chance that it will not work properly, which is a risk you take when you purchase one of these products.

There are two products out there that contain live bacteria, which will do the same job as finding some used filter media.  These products can be expensive!  There are other imitation products out there that DO NOT WORK, so be very careful.  We have only found these two products (BioSpira and Dr. Tim’s) to actually work properly a majority of the time.  When you get one of these products home, follow the directions on the bottle.  Assuming the product works properly, adding this product to your tank should immediately begin to remove toxins from the water.

Prime Dechlorinator
There is another product called Prime which acts as a dechlorinator.  As you should already know, dechlorinators remove chlorine and chloramine from your tap water (which is a MUST for any tank).  Prime does MORE than just dechlorinate; it also removes the Ammonia and other chemicals that are killing your puffer!  Prime is only a TEMPORARY fix, but it will allow you some time to figure out how to get the beneficial bacteria into your system.

If you decide to use Prime, perform 25% water changes every second day for the next few weeks (see below)!  It is a lot of extra work, but unless you can find bacteria from another source, it is your only option.

Water Changes
Water changes are one of the most important things you do for a fish tank!  If you went to the store and could not find any of the things mentioned above (used media/sponges, BioSpira, Dr. Tim’s, or Prime dechlorinator), your last resort is frequent, massive water changes.  Time to get the buckets out!  Massive water changes will be required to keep the toxic levels down until the bacteria establishes itself in the tank.

You MUST change out 75-100% of the tank’s water EACH DAY until the bacteria is established.

Unfortunately, it will take 4 to 8 weeks for the bacteria to establish itself, so you need to find a source of bacteria as soon as possible.  Look around for local fish clubs and ask for used filter media or sponges, or look around at various fish stores for the products mentioned above.

If you have followed these steps but are still having problems, please feel free to ask questions in our Hospital forum.

What should my tank readings be?
A tank with the properly amount of establish bacteria (also known as a cycled tank) will always produce readings of:

  • Ammonia:  0 ppm
  • Nitrite:  0 ppm
  • Nitrate:  less than 20 ppm (especially for puffers)

Nitrate is a toxin produced by the bacteria, but it is significantly less harmful to fish.  Nitrate levels are reduced when you perform water changes and is not a cause for concern unless your Nitrate reading goes above 20 ppm.  If you are consistently getting a reading this high, consult The Puffer Forum and ask for help.