Hi,

We are setting a second hand orca 450. we now have all the parts but no bubbles from the skimmer are collecting in the cup.

Should I raise the water level.

Also our NO3 levels are high on our Tetra 5 in 1 tester. all the others are ok. is it safe to put a couple of hermit crabs in. My son and I would love to see some action.

Thanks Grovey & son