Setting up a tank for aquatic turtles

The final frontier for me as a turtle keeper was Aquatic Turtles. To me, the whole concept of aquatics was daunting: So much more equipment, so much more work than tortoises. But, as it turns out, they are so much more interactive and fun, too, so it balances out.

Getting the right size aquarium

Aquatic turtles can grow quite rapidly during their first two or three years of life. You may start out with a tiny, two-inch-long hatchling, but by the end of first year, it will probably grow to at least three inches, if not larger.

Experienced turtle keepers recommend providing a minimum of 10 gallons of aquarium per inch of turtle. Thus, if you have a three-inch-long turtle, you should buy a 30-gallon aquarium. New keepers are often stunned to learn that they need to buy such a large tank for their tiny new turtle. Remember that buying a series of increasingly larger tanks for your growing turtle will be much more expensive than simply buying a large tank right at the start.

If you have a turtle that is longer than three inches, or if you have more than one turtle, you’ll definitely need to buy a bigger tank. A 40-gallon tank is the minimum size you should consider, and a 55- or 75-gallon tank would be even better.

[NOTE: Once your turtle reaches the size where it requires an aquarium of 100 gallons or more, it's really time for the turtle to go to an in-ground pond. If you cannot provide a pond, a large livestock tank can be used as a substitute.]

 

Other Equipment Needed for Aquatic Turtles

While an aquarium is the essential first step, there are several other pieces of equipment that you must get as well to keep your aquatic turtle successfully:

• An Undergravel Filter (UGF) plate that will fit inside and completely cover the bottom of the aquarium
• Gravel to cover the UGF plate at least three inches deep. (NOTE: A 50-pound bag of landscaper’s pea gravel from Home Depot/Lowe’s costs less than $5, and once rinsed, will be perfectly adequate. It's a much cheaper option than buying aquarium gravel from a pet store.)
• A multi-stage external canister filter to clean the water. The filter should have a flow rate of at least 250 gallons per hour and larger is always better. Make sure you remember to buy a few sets of replacement media for your filter. The following brand and models are recommended for turtle tanks:
  • Rena XP3 or XP4
  • Magnum 350
  • Fluval 305 or 405
  • Eheim Pro II 2126 or 2128
  • Marineland C-220 or C-360
• Tank furnishings -- including a basking area where the turtle can get out of the water to bask
• Lighting -- Turtles require special lighting to stay healthy. You should count on buying the following items immediately for your turtle:
  • A combination UV and heat bulb for the turtle’s basking spot -- Recommended brand is the 100 Watt MegaRay Bulb from ReptileUV.com
  • A dome lamp fixture with a ceramic socket -- A ceramic socket will tolerate the high heat produced by the UV bulb; plastic sockets will melt and catch fire so it's best to avoid them
• An unbreakable aquarium heater to keep the water at a constant temperature (typically between 75 and 80 degrees Fahrenheit)
• An unbreakable, submersible thermometer to monitor water temperature
• The following water treatment chemicals and test kits (available in the tropical fish section of most pet stores):
  • Biological filtration starter (Recommended Brands: Cycle, StressZyme, Stability)
  • Water dechlorinator and ammonia remover (Recommended Brands: Prime; Amquel Plus; AmmoLock)
  • A Freshwater Master Test Kit that tests Nitrate, Nitrite, Ammonia, and PH (Recommended Brands: Aquarium Pharmaceuticals; Red Sea; Mardel)

Keeping it clean: Water Quality Issues

Water quality is very important for keeping your turtle healthy and happy. Aquatic turtles produce a lot of ammonia-rich poop. This ammonia can build up in the aquarium water and if it is left untreated, it will poison your turtle. You need a way to remove the ammonia from the water. There are two ways to accomplish this:

1. Daily complete water changes, where you completely drain the turtle's tank and refill it with fresh water; OR

2. Provide enough filtration to keep the water clear, and the right kinds of filtration to keep odors and harmful chemicals low. A large multi-stage canister filter that is properly set up will perform biological filtration to remove ammonia from the tank water. These filters can also be fitted with carbon packs to remove odors and discolorations from the water of your turtle tank.

A biological filter uses beneficial bacteria to convert ammonia into nitrites. Other bacteria then convert the nitrites to nitrates. This conversion process is called the Nitrogen Cycle. It occurs naturally in lakes and rivers, and it what we want to reproduce in our turtle tanks.

This is why testing your water regularly is such an important part of aquarium-keeping. Testing and water changes are also crucial to prevent unhealthy buildups of ammonia or nitrites in the tank water because both of these compounds can harm your turtle.

Larger filters that move more water through them (more gallons per hour) are better at removing turtle waste than smaller filters. However, larger filters do have more suction power at their intake, which can be dangerous for small turtles or poor-swimming turtles.

 

Undergravel Filtration for Turtle Tanks

The best way I've found to set up a tank for aquatic turtles is to use an undergravel filter plate in combination with a large external canister filter. This technique was developed by Mary Hopson ( www.turtlepuddle.org).

Water is filtered through undergravel filter then through the external canister filter. By setting up the tank in this way, you will spread the suction out over the whole bottom of the aquarium, thus getting effective filtration without causing dangerous high suction areas that could trap and drown your turtles. The gravel bed serves two purposes in this setup. it provides mechanical filtration, removing large particles of food or plants to keep them from clogging the canister filter. The gravel bed also provides an area for biological filtration to take place. Nitrifying bacteria grow on the surfaces of the gravel, and this helps to break down ammonia and nitrites in the aquarium. This will keep the aquarium water cleaner.

Buying a good filter is costly, but it will significantly reduce the amount of effort involved in tank maintenance. Cleaning a filter once a week is a lot less work than doing full water changes every day.

 

How to set up your turtle tank

1. Rinse out the aquarium thoroughly with clean water ONLY (no soaps, detergents, or glass cleaners). You don’t know what might have gotten into the tank while it was in the store. You can probably rinse a 20- or 30-gallon tank in the bathtub; with larger tanks, it’s easier to put them on the ground outdoors and rinse them out using a garden hose.

2. Rinse the gravel that you plan to use in the aquarium. A plastic five-gallon bucket with holes drilled in the sides works well, but you can also use an old colander. Rinse as much of the dirt and dust off the gravel as you can before you put it into the aquarium.

3. Set the now-clean tank on a sturdy aquarium stand. Keep in mind that when you add the gravel and water to the aquarium, it will be extremely heavy. A good way to calculate the final weight is to allow ten pounds per gallon of tank – so a 40-gallon tank will weigh at least 400 pounds!

4. Put the UGF plate into the aquarium. The UGF plate will come with various tubes and caps. Insert one of the 1-inch clear tubes into one outlet of the UGF plate; cover the remaining outlets with the plastic caps supplied with the UGF. You will attach your canister filter to the one open outlet of the UGF.

 

5. Cover the UGF plate with a three-inch-deep layer of rinsed gravel. Make sure none of the gravel goes underneath the UGF plate or down the open outlet.

 

6. Set up the canister filter according to the manufacturer’s instructions. You may need to use a bit of creativity to attach the filter’s intake hose to the undergravel filter. The goal is for the water in the aquarium to be sucked down through the gravel layer and into the external canister filter, then be delivered back into the aquarium after it’s been properly filtered.

 

7. Add enough water to the aquarium to fill it approximately half-full. There may be residual dust on the gravel to make the water appear murky, but that will gradually clear as the filter draws the suspended dust out the water. If you use municipal or city water, it may be treated with chlorine. Add water dechlorinator in the amount specified on the bottle to the water in the aquarium.

8. Install your tank furnishings. Install the aquarium heater somewhere in the tank as well, making sure that it is submerged and that your turtle cannot get tangled up in the power cord. The heater should also be at least one inch above the gravel. Set the heater to 75 to 79 degrees F for hatchlings; adult turtles can be kept at 68 to 72 degrees F. Plug the heater in so that it can start working.

9. Turn on or plug in your canister filter and make sure it runs properly with no leaks. Add some of the Biological Filtration Starter to the tank and then let the filter run overnight to clear up and heat the water.

10. Get familiar with your water testing kit -- you should test your aquarium’s water at least once per week. The aquarium water should stay within these limits:

Ammonia:	0 to 0.25 ppm
Nitrite:	Zero ppm – nitrites are deadly to fish, and unhealthy for turtles
Nitrate:	0 to 50 ppm
pH:	Between 6.5 and 7.6

11. The next day, add plants to the tank. Your turtle will hide in the plants initially, but eventually will figure out that the plants are also food. Good choices for aquatic plants include water hyacinth, water lettuce, Anacharis, and duckweed.

12. Add a few inexpensive fish (I recommend feeder guppies) and some small snails to the tank to start the nitrogen cycle. The fish and snail poop will provide ammonia to feed the nitrifying bacteria. You should use your test kit to check the ammonia and nitrite levels at least once a day for the first two weeks or so to make sure that they are not building up to toxic levels. Watch the fish, too: if ammonia gets too high, they will be at the surface of the water, gasping for air. If they die suddenly, you've probably got nitrite issues. In either case, add the recommended amount (read the label on the bottle) of ammonia remover to the tank immediately to bring down the ammonia and nitrite levels. This process is called cycling the tank, and it can take as few as three days, or as long as two weeks. Basically, you are tweaking the Nitrogen Cycle until it stabilizes.

13. Add the turtles to the tank only after you've managed to get the ammonia and nitrite levels stable.