If you take care of fish in an aquarium, then it’s likely that you’ve asked yourself what rocks are safe for your fish tank floor. Well, as a spiritual person, I love sodalite and immediately started to wonder how well suited it was for fish tanks. Is sodalite safe for aquariums?
Well, the answer is: it depends on the type of aquarium you use. Due to the moderate hardness of sodalite, it has a tendency to dissolve in low pH water. If your aquarium is both cold water and with a high pH level, then your sodalite will be safe.
Is sodalite safe for aquariums?
Sodalite is a precious mineral. It is most common is blue or blue-violet in color and is often used as a gemstone. When in its raw state, sodalite is opaque, and can be used for decorative purposes.
Depending on where the stone is mined, the color can vary. Some can be red or pink and others grey or blue. The main deposits of sodalite are in Canada, Greenland and some parts of Asia.
Before introducing sodalite into your coldwater aquarium, you will need to check the pH of the water. If your water has a low pH, then avoid using sodalite. Where the pH is normal, or on the high side, sodalite will be safe.
The main problem with introducing sodalite is its tendency to dissolve. This only happens in low pH water. However, when you do use sodalite, use large pieces that have no sharp edges.
If you have a heated aquarium, then it is best not to introduce sodalite. There are many other equally attractive rocks to use instead.
Types of Aquariums
Before discussing the suitability of sodalite or other rocks for aquarium use, we just need to look at the different types of home aquariums available. Basically, there are four different types – Freshwater Tropical Aquariums, Cold Water Aquariums, Marine Aquariums and Brackish Aquariums.
Freshwater tropical aquariums
The most commonly found in use as home aquariums. They are easy to use, compared to the other types, the fish are less expensive and there are many different breeds available. These aquariums do need an electricity supply as the water temperature must be between 72 and 84 degrees Fahrenheit.
Cold Water Aquariums
These aquariums use freshwater at a temperature below 70 degrees. The most common fish kept in these conditions is goldfish. They are happy in water at room temperature, and will live happily in an aquarium with just basic equipment.
It is typical to use saltwater and require owners who are prepared to spend more time and effort in looking after them. Marine fish are less tolerant of poor water conditions, while some need special diets.
These are rarely found as home aquariums. Brackish water is a mix of saltwater and freshwater. There are very few types of fish suitable for home use, and they are mostly very particular about their water conditions.
What makes a rock unsafe for aquariums?
Rocks that have a high level of calcium in them are not suitable for use in freshwater fish tanks. Also avoid rocks that have magnesium in their make-up. Calcium-bearing rocks are fine for saltwater aquariums, as the water eco-system is different.
It is really important to avoid putting limestone in your freshwater tank. There is a simple test that will tell you if a rock is unsuitable. Just pour a little white vinegar onto the rock and wait. If it fizzes and bubbles, it is no good for your aquarium.
Sometimes, you might be tempted to use rocks that you have collected yourself. This is a bad idea, as some rocks will leach toxic elements into the aquarium water. Elements like arsenic and copper will prove fatal to fish.
Another hazard is the use of pesticides and herbicides. If a rock had been sprayed with either of these, it is likely that traces will remain on the surface of the rock. Some rocks will absorb the poison, so simple washing will not remove it.
Some people recommend cleaning self-collected rocks by boiling in water. Often scrubbing beforehand is also recommended, using a toothbrush to clean out any crevices. However, even this method does not guarantee that the rock is safe. You might be lucky, but it depends if you are willing to take a risk.
Boiling rocks can be risky, too. Some rocks will crack or even explode in boiling water. Some folk suggest pouring boiling water over the rock you want to use. Again, a risky manouver.
The safest option is to buy any rocks you wish to put in your aquarium from a pet shop. These rocks will be guaranteed safe. Even so, always wash any rocks you buy, just to clean off any dust or debris.
Are crystals safe for use in an aquarium?
Some crystals are perfectly safe to use in your aquarium. However, you should stick to the hard crystals, as they will not dissolve.
Here’s a list of those hard crystals that are great for aquariums:
· Clear quartz
· Smoky quartz
· Snow quartz
· Tiger’s Eye
· Rose quartz
· White jade
· Blue quartz
· Green quartz
· Zebra jasper
There are precious stones that are safe, including rubies, sapphires, emeralds, topaz and garnets. These do contain some aluminium but the levels are low and are unlikely to cause problems.
There is a long list of crystals that must be avoided. Here are a few of the mostly commonly found:
· Malachite, as it contains copper
· Cinnabar, which has mercury contained within it
· Mohawkite contains both copper and arsenic
· Chrysocolla is another crystal that contains copper
· Hematite contains iron
· Pyrites also contains iron
· Pyrrhotite, again contains iron
· Magnetite is another with iron contained in it
· Zircon, which contains zirconium and is radioactive
. Geodes are a bit risky, as the outer surface is often limestone based
Some aquarium keepers prefer to use crystals of various types and colors to brighten up their tanks. These keepers avoid using plastic items to provide color. Plastic is a by-product of the petroleum industry, and as it degrades, releases toxins.
The breakdown of plastic in water is very slow, but nevertheless it is kinder to your fish if you can avoid its use. The world is awash with plastic, so every little bit saved will benefit the planet.
How can you tell if a rock is safe for aquariums?
Certain fish are particularly sensitive to changes in the water they live in. It is therefore important not to introduce anything new to your tank that will change the water composition. You will naturally take great care when you change the water or clean the gravel, so be equally careful when you add any rocks.
The first thing you need to do is test the pH level of the water in your aquarium. A level of around 7.0 to 8.0 is ideal for most aquariums. Below 7.0 shows that the water is more acid, while above 7.0 the water is more alkaline. 7.0 is the neutral position, with neither acidity nor alkalinity.
Most tropical fish prefer very slightly acidic water, usually between 6.0 and 7.0. For example Clown Loach, Hatchetfish, Silver dollar and Tiger Barb enjoy a pH between 6.0 and 7.0. Angelfish and Zebra Danio like the level to be 6.5 to 7.0.
Neon Tetra prefer their water a little more acidic, between 5.8 and 6.2. Goldfish prefer a slight alkalinity ranging from 7.0 to 7.5.
Some fish find changes in the pH level distressing. Neon tetras are particularly prone to shock if they are moved and there is a sudden change in the pH level of their water. Take care to achieve the correct level of pH for your fish when setting up an aquarium.
This sensitivity to pH levels is the reason why introducing rocks into your aquarium must be done with great care. Changing the pH level might lead to poorly fish or even death.
If your fish are particularly sensitive to the pH level of the water in your aquarium, it is a good idea to test any rocks you buy. Put some of your aquarium water in a bucket and place the new rock in it. After 24 hours, test the water to see if there has been any change in the pH level. Do not use the rock if there is a noticeable change.
You can also test the suitability of rocks that might be limestone-based by using the vinegar test mentioned above. Just a little drop of white vinegar or a substance called pH Down, applied to a rock will soon tell you if it is suitable. Look for a fizzing and bubbling. If this happens, discard the rock. It will not be suitable for your aquarium.
We have already looked at those crystals that are safe for aquariums. Granite and slate can also be used quite safely. Avoid anything limestone or marble – use the vinegar test above to check. Lava rock should also be kept out of your aquarium.
How often should I clean my aquarium gravel?
Gravel covering the bottom of your aquarium gives two important benefits. Firstly it is decorative. Gravel can be sourced in a variety of colors, and choosing the look you want to create in your tank is part of the fun.
Secondly, gravel is important as a part of the aquariums eco-system. Fish waste, food waste and plant waste will all fall to the bottom and into the gravel. This takes it out of immediate harm’s way. Beneficial bacteria will attack this waste, and help to keep the water clean and your fish healthy.
Gravel also helps lower stress levels in your fish. They can nose into it and find scraps of food. Gravel will also give newly laid fish eggs a better chance of survival. If you have plants, their roots can grow into the gravel.
Having gravel in your aquarium will also mean less frequent cleaning. The bacteria living in the gravel will do much of the cleaning for you. For this to be effective, only use good quality gravel.
You should aim to clean the gravel in your aquarium once every two weeks. It will be fine to clean gravel when you are changing the water. When you change water, you only need change about a third of the water and the same applies to gravel. Clean about a quarter to a third of the gravel at any one time.
Clean the aquarium gravel using either a special type of vacuum, white vinegar or bleach. None of these methods take very long, but you must be thorough and exercise care to ensure no harm comes to your fish.
There are so many crystals and rocks that are safe for use in an aquarium that you do not need to risk using rocks that might be harmful. Using appropriate rocks and gravel can make your aquarium attractive and safe for your fish. The joy of owning fish is greater if you know you have taken no risks and that they are safe.