I have 4 discus and 2 have paired off and have already laid eggs, they laid the eggs on the filter return tube and I am worried that the fry will get sucked into the filter return. Can I place a sponge over it? Should I place a cup or PVC pipe flat or upright for them to lay their eggs?
1. You would put that pair of fish in a bare breeding tank for next spawning.
2. Now, to save the eggs already laid, you can stop the filtering system temporary and fix another air outlet to supply air.
3. When larvae free swimming, you can transfer them to the breeding tank.