Read this before you buy
The turtle in the shop tank is the size of a coin and costs less than a bag of fish food. Here is what nobody tells you at that moment:
- It will reach 25–30 cm — the size of a dinner plate.
- It will live 30–40 years, routinely. Some go longer.
- An adult needs 300–400 litres and a serious filter.
- It is messier than any fish you will ever keep, by an order of magnitude.
That is a four-decade commitment for an animal most people buy on a whim. It will outlast your flat, possibly your marriage, and quite plausibly your interest in turtles.
None of this means don't. A well-kept turtle is a genuinely rewarding animal — intelligent, interactive, and it will recognise you and beg at the glass like a dog. But go in with the real numbers, because the alternative is what this article is really about: the enormous global population of unwanted adult sliders, and the people who quietly release them into a lake and create an ecological problem that outlives them too.
Why a turtle is harder than a fish
People assume "it lives in water, so it is like a fish tank." It is not, and the difference is the thing that catches everyone out.
A turtle needs two complete environments at once:
- An aquatic environment — deep enough to swim, filtered, heated.
- A terrestrial environment — a dry basking platform with heat and UVB above it, where the animal can get completely out of the water and dry off.
And it eats like a small dog while producing waste like one. A turtle produces vastly more waste than a fish of the same size — they tear their food apart and scatter it, they defecate in the water they swim in, and they eat protein. This is why turtle water goes foul in days without serious filtration.
Which leads to the rule that governs everything below: filter for at least double the water volume you actually have. A filter rated for 400 litres on a 200-litre turtle tank is not overkill — it is the baseline. See Aquarium Filtration Basics, and then buy bigger than it says.
The numbers
| Target | Note | |
|---|---|---|
| Water volume (adult slider) | 300–400 L | A rough working rule: about 40 litres per 2.5 cm of shell length. A 25 cm turtle lands around 400 L. |
| Water depth | At least 1.5–2× shell length | They swim, they do not wade. But they must always be able to reach the surface. |
| Water temperature | 24–28 °C | Adults tolerate the lower end; hatchlings want the upper. |
| Basking surface | 32–35 °C | Measured on the platform itself, with an infrared thermometer. |
| UVB | Over the basking spot | Non-negotiable. More below. |
| Filtration | 2× the tank volume, minimum | The single most under-bought item in turtle keeping. |
Get the adult tank now. "I'll upgrade when it grows" means buying twice — and turtles grow faster than people expect. Also: a turtle tank is heavy. 400 litres of water is 400 kg before you add glass, filter, rock and stand. Check what your floor and your building can take, especially in a flat.
The basking area — and why it is not optional
A turtle that cannot dry off completely gets shell rot — a bacterial and fungal infection of the shell that is painful, hard to reverse, and entirely preventable. "Completely dry" means the whole animal, including the underside of the shell, out of the water, warm, for as long as it wants.
The platform must be genuinely dry and genuinely warm. A half-submerged rock is not a basking spot. A floating platform that sags under the animal's weight is not a basking spot. The turtle should be able to climb fully out and sit there for an hour with a 32–35 °C heat lamp above it.
And it needs UVB. Without UVB a turtle cannot synthesise vitamin D3, cannot use dietary calcium, and develops metabolic bone disease — which in a turtle means a soft, deformed, pyramided shell. That damage is permanent. The shell it grows is the shell it keeps.
Two things this country gets wrong, and they are the same two that catch reptile keepers here:
Glass and plastic block UVB. A turtle by a window gets light and warmth and no usable UVB at all. Sunlight through glass is not sunlight, biologically. And a mesh screen between lamp and animal cuts UVB significantly too — mount accordingly.
"Just put it outside in the sun." In a Dubai July, a turtle in a container outdoors can overheat and die in minutes — it cannot escape, and water in a shallow container heats fast. There is no safe version of this in summer. Use a proper UVB tube indoors, and replace it on schedule: UVB output decays long before the lamp stops making visible light. A tube can look perfectly bright and be doing nothing. Write the install date on it.
The full local argument is in Keeping Desert Reptiles in the UAE — the UVB and outdoor-sun sections apply to turtles identically.
The UAE-specific parts
Water temperature is usually not your problem — it might be the opposite. Most of the year, an air-conditioned room holds turtle water in range with the heater barely running. In summer, the risk flips: the tank climbs toward 30 °C+, and warm water holds less oxygen while a heavy bioload consumes more. A turtle can surface to breathe, so it will not suffocate — but your filter bacteria will struggle, and in a tank with this much waste that is exactly when the ammonia gets away from you. Keep the water moving and the surface broken. See How to Cool an Aquarium in a UAE Summer.
Evaporation is aggressive, and turtle tanks are open-topped by necessity (the basking lamp has to see the platform). You will top up constantly. Remember: top up with RO or distilled water, change with dechlorinated tap water. Evaporation leaves minerals behind; getting this backwards concentrates your water over a summer. Details here.
Dechlorinate everything. Chlorine and chloramine kill the filter bacteria you are utterly dependent on — and with a turtle's bioload, losing that colony is a fast trip to an ammonia crisis.
Feeding
The ratio flips with age, and this is where most long-term damage is done:
- Hatchlings and juveniles: largely carnivorous. Quality pellets, plus protein. Daily.
- Adults: mostly plant matter. Leafy greens, aquatic plants, with pellets and protein only a couple of times a week.
An adult turtle fed like a juvenile becomes an obese turtle with pyramided shell growth and organ damage. The overfed protein diet is the single most common husbandry failure in captive turtles, and unlike most mistakes it is written permanently into the animal's shell.
Calcium: a cuttlebone floating in the tank is the easy answer — they rasp at it when they need it, and it buffers the water slightly too.
Feeding trick worth knowing: feed in a separate container of tank water. It keeps the scattered food out of your filter, and it roughly halves your water quality problem. It is ten minutes of inconvenience that saves hours of maintenance.
Never: feeder goldfish as a staple (thiaminase, fat, disease risk), wild-caught anything, or dog and cat food.
The red-eared slider problem
The red-eared slider is the world's most-kept pet turtle and, not coincidentally, one of the world's most damaging invasive species — listed among the worst by the IUCN, banned from import in the EU, and established on nearly every continent.
The mechanism is always the same, and it is not malice: someone buys a coin-sized turtle, it grows to 30 cm over a few years, it outgrows the tank and the owner's patience, and one day they "set it free" in a lake or a park pond because it feels kinder than the alternatives.
It is not kinder. A released slider either dies slowly, or thrives — and thriving is worse. They outcompete native turtles for food and basking sites, they carry pathogens local species have no defence against, and they live for decades doing it. In an environment like the UAE's, where freshwater habitat is scarce and precious, this matters more, not less.
Never release a pet turtle. Not into a lake, not into a park, not into a wadi, not "back into nature" — it was never in nature.
If you cannot keep it: rehome it. Ask the shop, ask a local reptile or exotics group, ask a vet who sees exotics. It is a slow, awkward, unglamorous process and it is the only acceptable one. And note that laws on keeping and moving certain species vary — check the current rules for your emirate before acquiring or rehoming any turtle.
The honest conclusion: the best way to solve the slider problem is not to start it. If a 40-year, 400-litre commitment is not something you can promise today, that is a completely reasonable thing to know about yourself — and it is much better to know it now than in six years.
Warning signs
| Sign | Likely cause |
|---|---|
| Soft or flaking shell, white or pitted patches, bad smell | Shell rot. The basking area is not drying it properly, or the water is filthy. Fix both. Vet. |
| Pyramided, lumpy shell growth | Too much protein, and/or insufficient UVB and calcium. Permanent — the goal is stopping it, not reversing it. |
| Swollen or closed eyes | Often vitamin A deficiency, or water quality. Diet review, water change. |
| Floating oddly, listing to one side | Respiratory infection. Vet, urgently — turtles hide illness until it is advanced. |
| Never basking | Platform not warm enough, not dry enough, or hard to climb onto. Check the surface temperature. |
| Cloudy, smelly water within days | Under-filtered. This is the norm, not bad luck — double your filtration and feed in a separate container. |
Find a vet who sees exotics before you need one. Not every clinic does, and an emergency is the wrong time to discover that.
Common questions
Can I keep a turtle in a small tank while it is small? You can, and it will be fine for a while — which is exactly why people end up with an adult turtle and no plan. Growth is fast and the upgrade is expensive. Buy for the adult.
Can turtles live with fish? Turtles eat fish. Any fish small enough to catch is food, and any fish too big to catch still lives with a heavy bioload and a predator. Some people run it successfully with fast fish and huge filtration; treat it as an experiment with volunteers, not a plan.
Do I need a heater in the UAE? Usually yes, but it will do very little. Its job is a January night when the AC is off and the room drops. Set it and forget it.
Can two turtles share a tank? They can, and then one day they cannot — adults can be territorial and males harass females persistently. Two turtles need roughly double the space and a plan for separating them.
What should I buy first? Not the turtle. The adult-sized tank, a filter rated for double it, a basking platform that is genuinely dry, a UVB tube and a thermometer. Then run it, prove the numbers hold, and understand that everything you just bought is for an animal that may outlive the room it stands in. The habitat is the pet. The animal just lives in it.