Bacterial Infection: Empty tank: When is it safe?

[MKFish_2]

From the description I suspect a parasite outbreak, perhaps Uronema. External parasites can lead to secondary infection from bacteria, fungus, virus, etc.

Since you don’t know, I would let the tank lay fallow for at least a month. I think a UV can help, if properly used. It won’t cure a sick fish, but it will control or prevent an outbreak.

Best practice is to quarantine any new fish, or treat them prophylactically to prevent introducing disease to the main display. These require separate tanks.

You also mention an ‘explosion of copepods’. Is there macro algae in the system? If not, what do they feed on?

Here’s one reference on parasites to look over-

A Hobbyist’s Guide to Identifying Marine Aquarium Parasites

Awareness of the symptoms and treatments for other common parasites can save aquarists from disappointing setbacks, unnecessary expenses and the loss of livestock.

reefs.com

idk what they are eating I have no macro algae. just live rock, corals, a sea hair, and a cleaner shrimp

 

[ichthyoid]

The reason I asked is, large pod populations require significant food sources.

If you are feeding a lot, water quality ‘may’ become a problem and/or possibly encourage pathogens/disease.

Just wondering what your alkalinity, nitrate & phosphate levels might be?

 

[MKFish_2]

The reason I asked is, large pod populations require significant food sources.

If you are feeding a lot, water quality ‘may’ become a problem and/or possibly encourage pathogens/disease.

Just wondering what your alkalinity, nitrate & phosphate levels might be?

see im not feeding at all. I have no fish. I feed my sea hare in a separate "bowl" cause he struggles to get sea weed otherwise. I only reef roid my corals once a week and phosphate RX right after, so I truly don't know what they're eating other than my normal brown algae. Here are parameters

Ammonia: 0
Nitrates: 8
Phosphates: 0.04
My alkalinity checker broke so that I don't know