I use external controllers on several tanks using Ebo Jag,Stealth, and Won stainless and find this to be very efficient.It makes temp changing easy on the breeder tanks

Great Father and son project,well done,but where does he carry the goodies?

If you are trying to breed the angels I believe 10 corys in a 20 gallon would be a major distraction.As far as breeding them you failed to mention if you check your waters TDS. A tds around around 80 and a temp of 80 should produce the results you want.

Sara
What size tank, bare bottom or gravel,what foods are fed,what temp is tank kept at,how often are water changes and how much .How long has tank been set up and what other fish with them.Do you check water perameters?

Don
Your water does wonders on the Amaryllis,but also on your L333. Nice pictures of both.