Why Are My Cherry Shrimp Dying? What to Check First

Finding a dead cherry shrimp is upsetting, especially when the tank looked fine the night before. Before you start changing things, take a moment to look at what’s on the bottom and how the rest of the colony is behaving. A single pale shape might be a shed shell. Several shrimp struggling at once call for a prompt check of the water, temperature and filter.

First, check whether it’s a moult

Look from the side before reaching for the net. A moult often looks hollow and translucent, with a split around the head or upper body where the shrimp slipped out. A dead shrimp is more likely to look solid, with tissue visible inside. Colour by itself can be hard to judge, especially on pale gravel or under a bright light. If you can, take a photo through the glass and look at it from another angle. See how to tell a moult from a dead shrimp.

You can usually leave an empty shell for the colony to pick over. If you’re sure it’s a body, remove it so it doesn’t decay in the tank. Keep watching the other shrimp. A colony still grazing normally gives you a different picture from several animals sitting exposed and unusually still, swimming erratically or gathering near the surface.

Check the filter and temperature, then test the water

Make sure the filter is running and moving water. Look at the outlet and check that a sponge or intake hasn’t become blocked. If there’s been a power cut, note roughly how long it lasted. Check the actual temperature with a thermometer rather than relying on the heater setting. Think about whether the tank was in direct sun or the room became much hotter or colder than usual.

Test ammonia and nitrite first. Both should read zero in an established cherry shrimp aquarium. If you get an unexpected result, repeat it promptly with a clean vial, following the kit’s timing and mixing instructions. Check nitrate and pH too, and compare the readings with your usual results if you have them. If the problem followed a water change, compare the tank with the replacement water and include GH and KH in your checks. Write down the numbers and units so you can share them if you need help. What each cherry shrimp water test tells you.

If ammonia or nitrite is confirmed in a stocked tank, remove obvious waste and make a partial water change with conditioned water close to the tank’s temperature and chemistry. Restore normal filtration if it’s interrupted and retest. If several shrimp are struggling or deaths continue, contact an aquarium specialist promptly and share the readings. Ornamental Aquatic Trade Association freshwater shrimp care guide.

Think back to what changed

Run through the last few days in order. Did you change water, clean the filter, add plants or use a new product? Did someone feed the tank while you were out? A short timeline can turn a long list of possibilities into a few things you can check. If the trouble started just after a change, write down exactly what went in and when.

• Water change. Check which tap or supply you used, how you prepared the water and whether its temperature and chemistry were close to the tank’s. Check the conditioner label and the amount used against the volume of replacement water.
• Filter maintenance or loss of power. Check that water is moving through the filter again and that the intake is clear. If the media was recently replaced or rinsed under untreated tap water, include that detail when you ask for advice.
• New plants, treatments or sprays. Check the labels and ask the supplier whether new plants were treated with anything unsuitable for invertebrates. If you suspect an exposure, keep the packaging and seek prompt advice. Shrimp are sensitive to copper, and treatments suitable for fish can be unsuitable for a shrimp tank.
• Extra food or decaying material. Look behind the wood, underneath plants and around the intake. Remove obvious waste you can reach and check water quality. A clean-looking front pane can hide quite a lot at the back.

If it’s mainly the new shrimp

If the losses are among shrimp that arrived recently, contact the seller and ask what water conditions they were kept in. Share your tank readings, how you acclimatised them and when you first saw a problem. The fact that established shrimp are still grazing is useful information, but it doesn’t establish what happened to the new ones. Test the tank and compare the conditions before making another change or bringing more shrimp home.

If you’re seeing trouble around moulting, record what you actually saw. A body near an empty shell, a shrimp that appeared to be stuck, and an ordinary shed shell are different observations. A pale band or a single difficult moult doesn’t tell you which mineral to add. Check GH and KH alongside the rest of the water readings, and get advice if the pattern repeats.

Keep the next few checks simple

If you’re asking for help, include the size and age of the tank, when the shrimp arrived, how many are affected and what the rest of the colony is doing. A photo of the whole aquarium can show things that a close-up misses, such as where the shrimp are gathering or how the water is moving.

Once you’ve dealt with anything urgent, keep a brief log of what you changed and what the shrimp did afterwards. Note the temperature, water readings and any further losses. Use the same test method each time so you can see whether a number is moving or whether you simply read the colour differently. Avoid stacking several unconnected changes together while you’re trying to work out the cause.

It’s hard to stay calm when you’re worried about the colony. Start with the things you can actually see and measure. A clear photo, a few readings and a timeline of recent changes are useful whether you’re troubleshooting on your own or asking someone for help.