Ok, it looks like you have a serious problem here.
The floating granules could well be organic, but fish eggs are not likely in this situation. It is more likely bits of dead fish, from what you have just listed!
You are saying that the tank is cycled, have you checked the
ammonia and
nitrite readings? I can only assume that you have cycled the tank using the fish, which is always dangerous unless you can keep on top of it all the time. With the load that you have listed already, there is no way that the tank could ever cycle and support that number of fish!
How many fish have you got left? The first impression from your previous posting is that you stocked the tank almost immediately and looking at the fish you have lost, it was seriously overstocked to start with.
Let's see what we can salvage from this:
First of all, how many fish are in the tank now?
What is the ammonia and nitrite readings?
How often are you performing water changes and how much each time?
Your photo gallery indicates that you have several tanks, so is there a chance of re-locating any fish from this tank while it is stabilized? (This would need to be a separate tank, not one with fish in already)
popeye is a sure indication of poor water conditions. Several of your fish have suffered from this ailment.
redness around the mouth and gills is an indication of ammonia poisoning.
Lethargy can be caused by many different reasons, not least ammonia poisoning, but also through a variety of other ailments.
Ich is present in the tank and this will not get any better without treatment.
My remedy: (This is only my solution, not necessarily the way to go)
Do an immediate 50%
water change with dechlorinated water. Remove any
activated carbon from the filter and clean the filter properly in old tank water.
Raise the temperature to 32C and treat with an Ich remedy, and something like Prime or a stress-reliever.
Perform a 25% water change every day for the next two weeks, topping up the meds in the correct proportions each time.
Remove the floating debris and vacuum the gravel every water change.
DO NOT remove any fish from this tank to any of your other tanks yet, unless you can treat the two tanks the same way. they will almost certainly be sick now, even if they are not showing it, and putting them with other fish will just create a larger problem!
When the situation is under control, then you need to look at stocking levels in the tank. The rule of thumb is 1" per gallon of adult fish. To show how this works better, if your two clown loaches had survived, they would each be capable of attaining 16" each, so those two fish alone would have been too much for this tank! Add to that the sharks, 12" each, the cats, on average between 6 and 12" each, depending on the breed, and you can start to see where the real problem is!
I will PM some of the others that may be able to help with alternative solutions, or advise further treatments for this situation. please do not take offense at this post, we are here to help people in exactly your situation, and new members often start this way!
Good luck. I will alert the others and they will come and help too.