lava rock

Rocks out in the year may have been subject to fertilizers and/or insecticides. Lava is a somewhat porus rock which means getting bad stuff off.out of it may be hard. Be sure you know its safe in that respect.
 
soak the rock in a tub or bucket of water for about a week. change the water 100% every day. This should be enough to get any fertilizers or insecticides out of it. before placing the rock in the aquarium measure its temperature, by reading the temperature of water in the tub. Rocks can hold a lot of heat and may adversely effect temperature in your tank when you introduce them the first time. so be careful. once placed in the aquarium they act as natural temperature regulators in your tank.
 
wonder how it looks
 
wonder how it looks
lava.jpg
 
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