Check your local fish store. They should have mesh dividers. I would probably split a 10 gallon, and put plants by the divider so they wouldn't get stressed from seeing each other. You will have to cycle your tank again, but if you use the water they are currently in, it will jump start the cycling process. You could also purchase some biospira (you may need to order online) which is a bacterial additive (good bacteria) that can also help jump start your cycling process. Once you get past the cycling process, you should be doing water changes every 2 weeks (20%).
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Phishie
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