To answer your question on how you would go about doing this, the easiest way IMHO would be to create a PVC siphon driven overflow to send water from your 10g to your 5g. Then put a powerhead in the 5g which pumps water "up" to your 10g. Here's a link on how to build a PVC siphon driven overflow:
link
If you made the overflow out of half inch PVC it would probably cost you $3-$5 depending on if you already have PVC cement. As long as your 5g isn't to much lower than your 10g you can probably get away with a $15 powerhead. Assuming your 5g tank is $10 that's a grand total of ~$30 for the entire project.
Although I agree with the others that this doesn't seem worthwhile, I'm more than happy to provide any help I can.
link
If you made the overflow out of half inch PVC it would probably cost you $3-$5 depending on if you already have PVC cement. As long as your 5g isn't to much lower than your 10g you can probably get away with a $15 powerhead. Assuming your 5g tank is $10 that's a grand total of ~$30 for the entire project.
Although I agree with the others that this doesn't seem worthwhile, I'm more than happy to provide any help I can.
