Hello there,
I'm really sorry to hear about your situation. Losing fish can be really tough, especially after investing time and effort into creating a suitable environment for them. It sounds like you've been dealing with a pretty severe case of ich (Ichthyophthirius multifiliis). The steps you've taken so far, such as considering a quarantine and treatment with copper and antibiotics, are generally in line with recommended practices for combating ich.
However, as your fish have unfortunately already passed, the focus now is on maintaining your corals and invertebrates, and on preparing for the potential addition of new fish in the future. Here are some points to consider, some as other people have mentioned:
1. Time to eradicate ich: It's good that you're planning to let the tank sit fish-free for several months. Ich parasites need a fish host to complete their lifecycle, so without fish in your aquarium, the parasites should eventually die off. It's important to note that the length of time it takes for ich to be eradicated can depend on temperature, as ich has a faster lifecycle in warmer waters. If you're keeping your tank at typical tropical temperatures (around 77-79°F), a period of about 6-8 weeks is usually sufficient for the ich lifecycle to be broken. But keeping it fish-free for several months, as you're planning, will add an extra level of security.
2. Feeding corals: It's crucial that you keep the corals nourished during this time. Since you mentioned that you plan to feed them directly, you seem to be on the right track. Depending on the type of corals you have, suitable foods can range from specially prepared coral foods to zooplankton or phytoplankton.
3. Health of invertebrates: You mentioned that your shrimp, cerith, and stomatella are still alive. While it's true that invertebrates aren't affected by ich, they can still experience stress or malnutrition in a disrupted environment. Monitor their health and behavior closely.
As for questions, here are a few that might help clarify your situation and aid in providing additional advice:
1.What are the current water parameters of your tank (ammonia, nitrite, nitrate, pH, salinity, and temperature)?
2. What type(s) of corals do you have in the tank and how are they currently responding to the situation?
3. How often are you planning to feed the corals during this fish-free period?
4. Are there any other invertebrates in the tank that you haven't mentioned?
I hope this information is helpful to you. I feel for you and this is a stressful time, but rest assured, many hobbyists have faced similar problems and managed to reestablish their tanks successfully. I'm here if you have any more questions or need further advice!
Some references if you are curious:
- Colorni, A., & Burgess, P. (1997). Cryptocaryon irritans Brown 1951, the cause of 'white spot disease' in marine fish: an update. Aquarium Sciences and Conservation, 1(4), 217-238.
- Bower, C. E. (1997). The fish and invertebrate culture: water management in closed systems. John Wiley & Sons.
