Frequently Asked Questions
What kind of filter is best for a turtle tank?
The short answer is overkill filtration, regular 50% water changes, and occasionally algae control additives. Turtles are really messy creatures (as you likely already know) and will foul their water very quickly without adequate filtration.
For filtration, I recommend a canister style filter. They can be more expensive than other types of filters, but the investment is definitely worth it, plus they don’t usually use consumable filters so they can save money in the long run. In my experience the ‘over the rim’ style filters that hang on the top tend to clog up very quickly, and the replaceable filter cartridges can get pricey, especially when replacing them that often.
The general rule of thumb for filter size is to have a filter that is rated for 1.5-2 times the amount of water you have in your tank. For example, if you have a 40 gallon tank, get a filter that is rated for at least 60 gallons.
I currently have two aquariums housing my turtles, a 55-gallon and a 20-gallon Long. In the 55 I have a Fluval 107 Canister Filter along with a Top Fin 55-gallon hanging filter that came with my tank when I bought it. If I was doing it all over again I would just buy something like the Fluval 307 and just have one filter instead of two. In my 20L tank I have a Tetra Whisper filter that is rated for up to 30 gallons, and I have about 15 gallons of water in the tank.
Water changes are also important to keep your turtle healthy and their water clean. Over time the water in a turtle tank develops nitrates and nitrites from your turtle’s waste and food that isn’t eaten. When these levels get too high you’ll start to get algae growth on the walls and your water will become cloudy and (usually) green. By changing the water in the tank (draining and then refilling) you are removing the nitrates/nitrites. It depends on your tank size and turtle(s), but I would recommend doing a partial water change every one or two months, along with cleaning your filter. You can monitor the water quality in your tank using an aquarium test kit, they are affordable and usually are able to last for many tests. If you use tap water to fill your tank you should also use a water conditioner additive to remove any chlorine and promote beneficial bacteria growth.
If your tank has green water or algae growing on the walls that you can’t get under control, it’s likely either that your filters don’t have enough filtration capacity, your water needs to be changed more often, or both.
An interesting note, you should avoid doing a FULL water change in your turtle’s tank unless it’s very dirty and you need to ‘reset’ completely. The water in the tank depends on a balance of nitrates, nitrites, and beneficial bacteria to stay clean. When you completely change out the water you set all the levels to zero and your water can start to foul quickly. If this happens after a total water change I recommend doing partial water changes every other day until the water starts to clear up. You can also use algae control additives to help if needed.
If you don’t want to worry about it every again and money is no object go ahead and get this monster canister filter that should be enough to keep almost any tank clean.
What kind of substrate should I use?
There are a LOT of options for substrate, but you want to make sure that whatever you use is safe for your turtle. Aquarium sand is a fairly common substrate that can look really nice, but keep in mind that it will clog your filters, which will require more frequent cleaning/replacement. If your turtle is anything like mine they will dig around the churn up the sand like it’s their full-time job.
Gravel is also a good option, it gives your turtle something to play and root around in but won’t foul your filter. The only thing to watch out for with gravel is to make sure the gravel is too large for your turtle to swallow, as they are likely to swallow pieces if they are able to and they can get stuck in their digestive tract which is potentially fatal.
You can also opt to not use a substrate at all. This helps keep the tank clean since debris can’t get caught and built up on the bottom of the tank. You can also just use fewer, larger stones to have the best of both worlds.
How big of a tank does my turtle need?
The rule of thumb is to make sure your turtle has 10 gallons of water for every inch of shell length (head to tail). This starts to become unwieldy and expensive for larger turtles, for instance fully grown female Red Eared Sliders can have shells that are 12 inches long or greater. Since turtles are so long lived it can take them several decades to reach full size, so there is time to plan ahead for the size tank they will eventually need.
If you have multiple turtles you don’t usually need to multiply the gallon recommendation. You should take the shell length of your largest turtle, and you can add half the shell length of any additional turtles. So if you have two 10-inch long turtles, 150 gallons would be the recommendation (10+5 inches x 10 gallons = 150 gallons).
Once large turtles are reaching full size many owners will start to use alternate types of tanks, such as stock tanks or ponds as they are usually more economical at larger sizes.
Can I make my own basking platform?
Absolutely! I have listed out the materials I use on my platforms on their respective pages on this site. Feel free to make one with the same design as mine or customize it to fit your needs! I plan on eventually releasing detailed build guides and plans for all of my platforms, and if I have already they will be on this site!
How often should I feed my turtle, and what kind of food it best?
Hatchling and juvenile turtles(generally up to two years of age) should be fed daily. Adult turtles should be fed every other day, or three times per week. Turtles are very food motivated and will ‘act hungry’ at all times and they will likely eat as much food as you give them, but overfeeding can reduce water quality (from uneaten food and extra waste) and can also cause growth issues.
Turtles that have a diet too high in protein can develop ‘pyramiding’ on their shells, a condition where the shell starts to deform and grow in correctly, the most noticeable symptom is that their scutes start to build up into pyramid shapes. This condition is irreversible as once the shell grows irregularly it stays that way, but fixing their diet can stop the condition from getting worse. In the worst cases the shell deformities can make it harder for the turtle to walk, climb, and swim.