[keepsmiling]

Good morning. Yes, your biggest mistake was overstocking the tank before it was ready. So to keep these fish alive you are going to need to do a few things. First, what kind of test kits are you using and do you have one each,PH, Ammonia, Nitrite, and Nitrate? If not then get those, and get them in the liquid form{aka titration kits} API makes good kits. Test strips are not good as they are inaccurate.
If your ammonia is still at 4 ppm, do an 80% water change today and retest. You can add Seachem Prime too, even overdose a bit to help bring that down. You should have a large bottle of Prime to dechlorinate the water, and have on hand for spikes that are high. The next result you want in your cycle is a reading for Nitrite. Keep in mind this is even more dangerous to the fish.
What is your PH? Do you have an additional airpump with airstone? Is the filter making movement at the surface of the water?
Do as many water changes as needed to keep the parameters at a reasonable level until the tank is done cycling. After that you mostly monitor Nitrate and change your water to keep them under 20 PPM.{do the other tests periodically}

 

[keepsmiling]

Moving some fish to the other tank will help ease the load on the new tank. Monitor and keep that water changed as well. FEED SPARINGLY right now, and avoid any fresh foods and bloodworms for now.

 

[keepsmiling]

Keep a close eye on the 30. I would have rather seen you move another type of fish since you say the angels are "large".
But two weeks fishless may have changed the parameters. Check and make sure all parameters are ok in the 30.

 

[keepsmiling]

Ok, sounds good. Try adding some Prime today to cinch that ammonia a bit more. If the tank with the angels has 0 nitrates you lost the cycle there as I suspected. Keep a very close eye on it. It might just be a mini cycle, in which case the process will happen quickly. You can feed them sparingly.