Glad your gouramis are getting along well. I probably just had a grouchy bunch LOL. Sorry to hear about your nitrite spike. Did you maybe get a little overzealous on a gravel cleaning? Maybe changed the sponges in your filter? Either of those can send the tank into a mini cycle. Water changes are good to help get everything back to normal. Prime can also help detox the nitrite for the time being to help ease the stress on the fish while your tank stabilizes.