BRT LArval rearing system

Its been a long year and between family health problems and summer, I have not tried to raise any fry since January. Right now I have three pair laying, skunks, black Darwins, and ocellaris. I have time right now to raise a batch or two and my rotifers arrived today. The black pair will have a hatch tonight.....just in time.
I am trying the new and lazy method of raising the fry. NO WATER CHANGES. If you look at my BRT you will see it has a bottom input for water and an overflow out the top. This allows new water to enter just below the bubble ring and the upwelling circulates it. It then must pass through the filter on the overflow and return to the sump. Rotifers and fry stay in and water from the main system is dripped into the BRT on a continuous but very slow rate. I have tried to set it up so that the 7 gal in the BRT is turned over twice daily. The amount of waste coming from the BRT will be dissolved organics and ammonia. The overflow filter catches the fine particles.
By contrast, each of my breeder tanks gets fed 3 times a day with feeders and once a day a feed Fertility Frenzy. That's a lot of food and it is well handled by my oversized ATS and the size of the system.
I think it will have a very small effect. I have had 8 breeder pairs on this system before and I don't see the amount of food going into the BRT being anywhere near what two adult breeding fish will consume.
We will see, I have to go unpackage my rotifers from Reed mariculure.

 

I raise clowns occasionally. I have a small set up that allows me to raise a clutch or two when it is convenient for me to stay home for a month. I have feeders on all of my tanks and I leave for up to two weeks on occasion.
My system utilizes a BRT that is hooked to the system and water circulates through it at a very slow rate. It has a central drain and that’s protected by a foam filter. The eggs are allowed to hatch in the BRT and then it is fed rotifers and green water. The turnover is so slow that the BRT needs to be heated. \
So on November 7th I put a pot with Darwin eggs into the BRT and they failed to hatch by day 10. Four days later I introduced a pot of skunk clown eggs and they too failed to hatch. I knew I was going out of town for two weeks at Christmas and there wasn’t enough time to try another clutch so I put my rotifers in the fridge, turned off the heater in the BRT and pulled the foam filter. The circulation continues but the temperature drops to about 70 F. I have since discovered that the timer on the light over the BRT wasn’t working and the light had been staying on 24/7 and was the probable cause of the no hatches.
So yesterday I was getting the BRT ready again. I was checking the air flow and wiping it down when I saw a baby clown. It is fully striped, but I am not sure what it is. It has been living and growing in the BRT with very little circulation and no heat. There were rotifers and green water left in the BRT when I pulled the filter in November, knowing that they would eventually die or go into the sump.
The mystery is how the fry got into the BRT and how it survived with no care for 60 days, at 69 – 70 F.
I was going to start another clutch of skunk clowns yesterday, but I had to get the BRT up to temp first. I was thinking the small survivor would have trouble with the rapid change in temp. I raised the temp slowly and passed on the skunk eggs. This morning I fed the little guy TDO B1 and he loaded up. My best guess is that it is a small Darwin based on the striping, but with the BRT full of green water it’s hard to tell. I also have Ocellaris clowns in the system that are breeding, but haven’t tried to raise any lately.