Ammonia and nitrite are each at .25
My real concern for you is the nitrites. Ammonia is bad, but clowns and their fry are fairly tolerant of ammonia. Nitrites, however, are deadly. Amquel is good. Chloram-x is better, but if you are showing measurable nitrites, then I would consider a water change. Problem is, water changes at this stage can be catasrophic for fry. They are difficult and time consuming. The way I see it is you have several choices. 1. Continued dosing and a very slow and methodical water change. Nothing more than a drip per second going in, and about the same coming out. 2. dose amquel heavily until meta and hope for the best. 3. Take a small piece of LR out of your display and place it in your fry tank right near the bubbles. A lot of people won't agree with this idea, but it has worked for me in the past. Even a golfball sized piece will have a good impact. This with continued dosing should do well.
Here's the rub... What you've got right now is a tank that's cycling...and cycling hard. When it comes to fry, the best we can do is try to mitigate the severity of any cycle that may take place. I think you pulled the tile early??? Not sure, but either way I'm pretty sure you used parent tank water. This introduces a significant amount of nitrifying bacteria into your fry tank as would the tile, if left in the fry tank for an extended period of time. Not a bad thing necessarily, but it will kick off a cycle. Depending on how much bacteria, and how much waste is present (algae paste should help in this area as well) it can cause a large nitrite spike and cause total collpase of the system. dosing will help but if possible, be ready with a well seasoned sponge filter. I've added a sponge filter as early as day 5, but I've never really been able to give it enough air to work well until around day 7. You will most likely need to do small but frequent water changes much earlier than you might think. All depends on the chemistry. I don't trust amonia alert badges...been burned before...traditional testing is annoying, but much more reliable IMO.
The strange thing is that I've actually had better success using newly mixed salt water instead of parent tank water, and although it always causes higher ammonia levels, I can usually get to day 7 without any substantial nitrite spike. Ammonia toxicity is an issue when you raise PH, but if you vaccum the bottom of your tank every day, and do very small, frequent water changes with NSW, you probably won't have as bad an issue with the PH. Either way, a large amount of ammonia is an irritant which can eventually become life threating while nitrites are straight up poison.
If it were me...I'd throw a chunck of LR in there, do a small water change like maybe 2 quarts, dose with amquel, put an airstone on the end of the rigid tubing, crank up the air volume just a smidge, and monitor the temp. 78F is not bad, and I always get myself into trouble when I try to monkey around with heaters. Probably because I tend to buy cheap ones, but even the name brand ones I have seem to be very touchy.
Most importantly, don't stress out. Now that your clowns are laying, you are going to have more chances than you will ever need. Within the next few hatches, everything will fall into place, and you will find yourself inundated with baby clowns. 200 - 300 ever 11 days or so.
My 2 cents anyway. I love hearing about your babies!! takes me back.
oh and as far as lighting. I would just use the overhead light. Breeding clowns is more of an art than a science, at least at the home breeder scale, but I feel confident in this one piece of advice.