Hello turtles masters :)

I have 20cm (shield) turtle in 70L of water in aquarium.enter image description here

As a filter I use Repti Clear F350 (276L/hour 6W).

I also use ReptoFresh and ReptoSafe.

Problem: Even I clean the filter almost every day (it get dirty fast) water can be pretty dirty in a week. I don't wanna change water every week. I have read some articles in which people change water every second week, but some of them change it only once a year.

Question: Is there something I can do in order to keep from doing water changes every week?

I'm wondering if I should be using a different filter or caring for it differently? Would adding any natural "filters" like plants or even fish (which could not be eaten by my turtle) help?


1 Answer 1


There are a few ways to reduce the frequency of water changes for your turtle. Just keep in mind there is no running away from water changes.

  • Have an efficient biological filter: This very obvious way is probably the most important. I'm not particularly sure about the filter you have, but essentially in turtle tanks you want to cycle the water at least three times an hour, so since you're keeping the turtle in a 70L aquarium, you need a pump that cycles 210L per hour. Keep in mind many pumps just claim to cycle that much, so as long as the intake doesn't disrupt your turtle, the stronger the better. Also make sure your filter has efficient bio media like ceramic rings and bio balls. Sponge only filters usually don't do too much biological filtration.

  • Increase your water volume: This is something I personally really want to point out because it won't only help you with your water changes but it'll be of greater service to your turtle. Get a bigger tank; the bigger the tank, the more diluted the wastes are, and the less the need for water changes. The rule of thumb is 10 gallons of water for every inch of turtle shell. I like to further specify to surface area, since the depth of the water isn't direly important to turtles: at least 600cm squared per inch of turtle shell. I understand that larger tanks are pricy, but the turtle doesn't really care if it's an aquarium; it may as well be any water holding container like a kiddie pool or a stock tank.

  • Do not overfeed: Turtles will beg for food all day; they are very opportunistic and will eat everything you offer them. Instinct tells them to snatch every chance because, at least in the wild, they never know when the next meal is coming. Not only will overfeeding dirty up your tank quickly, but it is also unhealthy for the turtle, leading to hygienic issues and organ failure. Just a note here, adult turtles should not be fed daily, you can feed the turtle 3-4 times a week.

  • Have some aquatic plants: Aquatic plants consume chemicals toxic to turtles, unfortunately for you, it is going to be very hard to grow them in a small tank with a potentially ravenous turtle. Getting a bigger enclosure, again, will not only dilute wastes and give room to your turtle, but it will also potentially enable you to grow some aquatic plants and have other organisms in the tank.

  • Do partial water changes: You can Instead of changing the water completely every two weeks or so, change, 20% of the water every few days. And about the once a year change, that isn't an option, whoever said he does so, is either wrong, or has a very large enclosure with a very efficient filter.

  • Feed the turtle in a separate container: You can just have a relatively small bowl or container to feed the turtle in. You can just fill it with some water and offer your turtle some food. And in order to change some water in the process, you can take the water from the tank and replace it. That way you'll be doing gradual water changing too.

    As for adding fish, the turtle will probably eat them all, especially if it sees you dropping it in the tank, it's likely to directly consider it food. And if it doesn't, it might hunt it down when it's bored or hungry. Not to forget that fish produce their own wastes too.

    As a side note, make sure the lamp you have for the turtle is a UV lamp as it is essential for the turtles health, also, don't clean the filter media too often or vigorously as I hear it may remove some nitrifying bacterial cultures from there.

  • 1
    N.b. 10 gallons per inch of shell ≈ 15 liters per cm.
    – augurar
    Jan 6, 2015 at 3:45
  • My filter cycle 276L/hour so that be OK ragarding to your answer. It should has biological, chemical and mechanical filtration. exo-terra.com/en/products/repti_clear_f350.php so I consider weekly watter change as too often :/
    – Luxqs
    Jan 6, 2015 at 17:02
  • Space for turtle can not be bigger for a few months.
    – Luxqs
    Jan 6, 2015 at 17:04
  • 1
    @Luxqs Problems you may have include: your filter has become weaker, this does happen, filters are always the most powerful the first time they run. Two, is the size of the enclosure, which I think is the real problem. You have quite a large turtle and turtles really do dirty up the water very quickly, I say you need at least a 70 gallon for this turtle, or an enclosure that measures 80*60cm or anything that adds up to 4800cm² in surface area of length and width.
    – Mozein
    Jan 6, 2015 at 17:26
  • 2
    @Luxqs and in case you didn't know, the carbon cartilages in your filter need to be replaced frequently or that can cause problems
    – Mozein
    Jan 6, 2015 at 17:31

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