(Sometimes I rush to post answers, so I figure a quick picture link is worth a thousand poorly explained words! :roll: )
So, you need:
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Materials:
1. An air pump... stores or online places that sell aquarium stuff will have these. Some are noisier than others.
2. Air tubing. Also aquarium supplies.
3. Air stone... different shapes exist... all will get the job done, so don't stress.
4. A pair of nesting containers: food containers work well.
Optional: a splitter or fancy gang valve for turning an air line for one pool (fresh or salt) into a bubbler for two pools (both fresh & salt). Ask people how best to do this, it's easy, but opinions vary.
Stick one end of the airline to the hole in the pump:
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Stick the other on the airstone:
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Then put rocks (or whatever) in the container that wont have water in it... bury it in the sub.
Next, take the container that will have water in it, and place this container in the buried one.
Add water.
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Add bubbler, plug in, and voila! Improved humidity - just make sure the lid is good & sealed, or your humidity will escape!!
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