Selecting Aquatic Turtle Food

Selecting Aquatic Turtle FoodBesides underestimating the enclosure size and filtration needs of most turtles, misconceptions about turtle food and feeding are the next biggest cause of failure.

What constitutes a “correct” turtle diet is still an emerging question, just as it is with humans, and there is no single answer for all aquatic turtles, since each species is adapted to different food sources that are available in their respective environments.

The good news is that, unless you want to do a dissertation on the subject, for the vast majority of aquatic turtles you need not get bogged down in esoteric debates about nutrition. This is because the key dietary requirements of virtually all aquatic turtles are very similar, and can typically be met by using a high-quality, fortified prepared food, in conjunction with a rotating selection of fresh or dried foods supplemented with some vitamins.

Let’s break this down into some easy action steps.

1) Select a High-Quality Prepared Turtle Food as a Staple

For most of us that do not have the time or the luxury to catch or culture a wide variety of the foods an aquatic turtle is likely to eat in the wild, a high-quality prepared food is not only smart, but can form the backbone of a well-rounded diet. Note: I am not talking about turtle “bites” or freeze-dried krill or other “treats,” which may be appealing to your turtle but don’t provide balanced nutrition. In addition to providing a great protein source, good brands will typically be fortified with vitamins and minerals, most notably calcium. Besides D3, which we’ll discuss later, sufficient levels of calcium in a turtle’s diet is absolutely critical for proper bone and shell development. Calcium deficiencies are one of the biggest health risks for turtles that are fed a high-protein, unvaried diet. A turtle food that contains calcium is definitely a good start towards balanced nutrition. In fact, if any inexperienced turtle keeper decided to forgo a prepared staple food, I would be very concerned. However, don’t overdo a good thing; prepared foods should generally make up no more than half of your turtle’s total caloric intake to ensure a healthy variety.

Which prepared food you select is a matter of preference, but all of the following brands are good choices and make a great staple:

Rep-Cal SRP00810 Aquatic Turtle Food

In my view and many others, Rep-Cal produces the highest quality supplements for reptiles you can get.

Thus, it’s not surprising that they would come out with a super-complete aquatic turtle food that is fortified with all necessary vitamins and minerals, including both calcium and vitamin D3. It is reportedly 100% complete!

This is a very big deal, and can save you money and a lot of time trying to coat other foods with messy powders or other stubborn supplements.

As you’d expect with such a complete staple, it is both veterinarian-tested and recommended. This is easily the best available turtle food staple out right now, and the one I would most recommend.

Tetra ReptoMin Sticks

ReptoMin sticks are a floating dried food that has been used by newbies and veteran turtle keepers for decades. Why?

Because ReptoMin is a fairly well-balanced prepared food and is fortified with calcium and vitamin C.

While not as complete as the Rep-Cal food above, it is very inexpensive as far as a turtle staple goes, and most aquatic turtles will accept this food without hesitation. What else do you want?

Just make sure to presoak the sticks a bit for hatchling turtles , which otherwise may have a hard time breaking them up.

Tetra ReptoMin PLUS

ReptoMin PLUS is another version of the ReptoMin stick formula that provides the same basic nutrition.

This formula differs in including red “shrimp” bites as an additional protein source. These reportedly consist of shrimp and krill.

While I’m not certain this is necessary, this “premium” formula is getting great reviews and appears to be eagerly accepted.

Although it is a bit more expensive, it is still a very reasonably-priced stable and definitely worth a try if you like the traditional ReptoMin product.

Tetra ReptoMin Sticks, Reptile Food, 6.83 lbs

This is the same Tetro ReptoMin formula first listed, except it comes in a huge, nearly 7- pound container that will keep you and your turtle in good shape for a long time.

As many turtle keepers are keenly aware, buying in bulk is definitely the way to go, especially if you are feeding mature turtles.

It’s like a costco-sized product for turtles, a darn good idea.

In our view, you really can’t go wrong with this formula and the tremendous bang for your your buck you get with this “bucket” of turtle food!

Zoo Med Natural Aquatic Turtle Food

Zoo Med is always at the forefront of reptile care, and its Natural Aquatic Turtle Food is a good choice as a staple.

In addition, it comes in three formulas, for (1) hatchlings, (2) maintenance and (3) growth, which address the varying needs of turtles based on life stage.

As a general rule, most commonly available sun-bathing turtles species (e.g., sliders and painted turtles) are more carnivorous when hatchlings and gradually move towards a more omnivorous lifestyle as they mature.

2) Rotate Among Various Types of “Fresh” Turtle Food

With the possible exception of the Rep-Cal food mentioned above, just about every prepared food will be deficient in some way. Moreover, there is no question that turtles will benefit from a varied diet and the myriad of vitamins, minerals and anti-oxidants that occur in fresh, whole foods. After all, there is just so much that you can put into a dried pellet, and many compounds can only be found in fresh foods as they are prone to rapid oxidation. So, do yourself and your turtle a favor and make sure to rotate through a variety of additional fresh foods. In total they should amount for roughly 50% of your turtle’s total food intake.

Here is a list of some good options that you should introduce to your turtle. Just make sure that you in fact rotate these foods; avoid fixating on just the ones that your turtle greedily accepts. In captivity, an aquatic turtle’s nearly universal preference for proteinaceous, fleshy foods can and will lead to deficiencies and obesity. With the exception of vegetables (which your turtle will rarely abuse!) and earthworms, which are a remarkably good fresh food, treat all other items as treats and don’t give in to hungry stares. Think of it as humans’ tendency to gorge on salty, fatty and sugary foods.

Leafy greens are a necessary, but easily overlooked aquatic turtle food.Leafy Greens

Even if you are keeping relatively carnivorous, highly-aquatic turtles, like side-neck, musk or snapping turtles, try to offer a variety of vegetable matter. Most turtles will accept some vegetation in their diet. Good choices are Elodea/anacharis, romaine lettuce, duckweed, watercress, green beans, kale, carrot, squash, zucchini, and bits of young salad greens (like that in a spring salad mix). Also try some fruit, like melon, blueberries, and figs. Mix things up and be persistent. Try to give your turtle as much vegetable matter as you can. There is virtually no way to overdo vegetables!


Did you know that earthworms and night crawlers are an amphibian/reptile superfood?

Earthworms, with their high calcium to phosphorous ratio, may be the perfect natural turtle food!

One of the most important things in reptile nutrition is the ratio of calcium to phosphorous. Because phosphorous is believed to negatively impact calcium availability in a particular food, you generally want foods that have a relatively high proportion of calcium to phosphorous. A ratio greater than “1” is considered ideal. Earthworms excel in this regard and are an outstanding source of precious calcium. For example, take a look a this comparison chart of the nutritional value of a variety of amphibian foods. Nightcrawlers and earthworms have a calcium to phosphorous ratio of 1.58 and 1.91, respectively! This is far better than most typically provided fresh foods, which have a low ratio, such as adult crickets (0.14), bloodworms (0.42), mealworms (0.14), raw shrimp (0.26), beefheart (0.03), maggots (0.36), and cockroaches (0.40). Moral of the story – feed your turtle earthworms often!

Other Fresh & Dried Foods

Crayfish are often found in stomach content analyses of wild aquatic turtles.

Other fresh foods that your turtle can benefit from in moderation are things like crickets, bloodworms, mosquito larvae, blackworms, tubifex worms, crayfish, krill, shrimp, live whole snails, small live fish, and lean pieces of meat – beef heart usually being a good choice. As we’ll discuss below, beef heart should be liberally coated in a good calcium supplement before feeding, given how devoid of calcium it is. All of these foods are beneficial in their own way, but are all easily abused by your turtle given half a chance. Consequently, they should be fed sparingly.

3) Use UV-B Lighting If Possible

While vitamin D3 can be supplied in the diet by using a very complete enriched food (like the Rep-Cal turtle food above) or with a supplement, using a UV-B emitting bulb is one of the best ways, as UV-B light allows a turtle to synthesize its own stores of this vitamin.

A combination heat lamp and UV-B bulb (like the Zoo Med model to the left) is particularly convenient and easy to use.

Using a light source obviates the need for metering out messy powders that tend to wash off, and it’s a very natural and effective way for aquatic turtles to make vitamin D, especially sun-worshiping species like sliders, painted turtles, map turtles and cooters. Nevertheless, even for more highly-aquatic turtles such lighting is a good idea, since some vitamin D3 can be synthesized even under relatively brief exposure to this light. For turtles that are kept outdoors and receive natural, unfiltered sunlight – i.e., light that does not pass through glass or other coverings – no additional UV-B lighting or vitamin D3 supplementation is necessary.

4) Use High Quality Turtle Food Supplements

In ideal circumstances, your turtle would get all of the macro and micro nutrients, vitamins and minerals needed solely through dietary sources. But just as people take multivitamins to supplement their food, so should turtles. Think of it as a nutritional safety net to help keep your turtle in peak health and avoid deficiencies and/or various ailments that can be brought on by an imbalanced diet. While there are numerous reptile vitamins on the market, if you are generally following the plan above, you really only need one of the following two additional supplements:

Rep-Cal Reptile Calcium Powder with D3

For turtles that are not receiving UV-B light, or are not basking regularly to take advantage of it, I strongly recommend Rep-Cal Reptile Calcium Powder with D3.

Rep-Cal is far and away the best name in supplementation for reptiles, and in my opinion the only supplement brand to use.

This calcium/D3 combination kills two birds with one stone – it provides an extra boost of calcium (which most turtles can’t get too much of) and it provides D3 simultaneously.

It is not cheap, but this stuff goes a long way. Do not make the mistake of going for some other brand, take my word for this!

Rep-Cal Phosphorous-Free Calcium Powder without Vitamin D3

If your turtle is enjoying a UV-B emitting lamp, or is being fed the Rep-Cal food mentioned above (already fortified with D3), or is being kept outdoors in completely unfiltered natural sunlight, then you don’t need exrtra D3. But your turtle can still benefit from additional calcium, in which case I’d recommend Rep-Cal Phosphorous-Free Calcium Powder without Vitamin D3.

Calcium supplementation is really a necessity in my experience, even if using fortified foods.

This is particularly true for fast-growing hatchlings which can suffer from permanent shell, skeletal deformation from even a transient calcium deficiency.

Applying these powders can be tricky and take a bit of trial and error with aquatic turtles to prevent them from being washed off. This stuff sticks well on moist foods, like beef heart, which should always be supplemented anyway since it contains virtually no calcium. You can even dust it onto moistened turtle sticks or pellets, and let it dry on for a while. Some have recommended making a liquid out of it and using it to hydrate dry foods, like trout pellets, bits of dog-chow or prepared turtle food.

5) Don’t Overfeed Your Turtle!

Sounds simple enough but it is the most common reason why long-term captives suffer.

Even the best turtle foods can be harmful if overfed!Turtles kept in even large enclosures still have only a tiny fraction of the space they would in the wild, and therefore have much more modest caloric needs. In addition, the foods typically offered to pet turtles are far richer than that a turtle would normally encounter in the wild, and a turtle in the wild would have to actively search for it and therefore expend more energy in the process.

It may be hard, especially when your turtle quickly figures out that your looming presence =  food; but you must be strong. As a general rule, you can feed hatchling turtles everyday, but only an amount that they can finish off within 10 minutes. As they mature, you can begin to alternate feeding days. And once they are getting close to typical adult sizes, start feeding them as much as they can consume in 20 minutes, but only 3 times per week. Remember that these are cold-blooded animals that do not need to waste energy maintaining body heat, as mammals must do. So despite how hungry they appear to you, they do not need to eat more often than this, especially when mature. An overfed turtle is ripe for all kinds of health problems and is vulnerable to infection. Moreover, overfeeding can potentially shorten their lifespan as it puts enormous strain on organs. Don’t do it!

For more information about aquatic turtle food, check out this handy article from the Tortoise Trust.

Photo credits (in order of appearance):

Denise Chan under CC BY-SA 2.0

Robert Couse-Baker under CC BY 2.0

Allan Henderson under CC BY 2.0

Darell Licht under CC BY-ND 2.0

CrunchyLens under CC BY-SA 2.0

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