Can you use tap water?
Yes, using tap water in your shrimp tank can also be simpler than mixing your own water with a remineralizer. This is one reason why a lot of beginners start with tap water tanks.
However, even though you can use tap water, it still has a few risks and downsides you need to be aware of.
You should only really use tap water for Neocaridina tanks, unless you have very soft water.
Risks with using tap water
- Unstable water parameters
- May contain unsafe chemicals
- Old copper water pipes can create toxic water for shrimp and snails
Unstable water parameters
The main downside to using tap water is that the water parameters can vary quite a lot.
Shrimp thrive with stability, so the swings in parameters from water changes can stress them out a bit. You'll have much more success with breeding if you can keep everything consistent and stable.
It's a good idea to test your tap water to get a rough idea of how suitable it is for your chosen species of shrimp. These are the parameters to check:
- General Hardness (GH): The amount of calcium in the water, required for shrimp to build healthy shells and molt safely
- Carbonate Hardness (KH): The amount of carbonates in the water, to buffer the water from pH swings
- Total Dissolved Solids (TDS): The total amount of elements dissolved in the water, this gives a rough idea of how clean the water is
Looking at just the TDS value isn't very useful on its own, it only tells you how much stuff is dissolved in the water, but not what it is.
This is why it's important to test the GH and KH too.
Tap water will almost always contain chemicals to make it safe for humans to drink, like chlorine. These chemicals are highly toxic to shrimp, even low doses can cause death.
To deal with these chemicals, you'll need to use a dechlorinator, sometimes also called a water conditioner.
At a very simple level, the water conditioner will cause chemical reactions with the dangerous chemicals, converting them into safe elements.
Seachem Prime is the most popular water conditioner, and it's very handy to have around. It can also be used in emergencies for ammonia spikes, making the water less toxic until you can perform a water change and fix the cause.
Potential copper poisoning
Some old water pipes can deteriorate over time, and cause small amounts of copper to come out with the water.
Copper is highly toxic to both shrimp and snails, and can cause deaths even in tiny doses.
This is a fairly low risk, and chances are your water is fine. Having said that, if you do start noticing deaths from water changes with tap water, definitely test it for copper.
To sum it up, tap water can be totally safe if you test it before using it in your tank.
Make sure you always dechlorinate the water before adding to your tank.
As the water parameters can fluctuate a lot, you should drip acclimate new water back into your tank with water changes.