View Full Version : Dan's many larvae questions (because he's obviously a newb)

01/29/2016, 10:44 PM
So I have just decided to start a single thread to ask all of my obnoxious questions rather than cluttering up the breeding forum. (Yes, it has come to this...)

So, tonight's question:
I collected 500 or so ocellaris larvae last night using a Vossen trap, and also siphoning them with airline tubing. Transferred to 5 gallon kreisel filled with broodstock water, and later the next day (today) were transferred to a 2.5 gallon with water from the kreisel (explain in a bit). All larvae lived through the night in the kreisel, and I added rotifers and greenwater, and began to gradually light the tank at 7am. A few hours into the day today, 200 or so we're dead on the bottom, 100 or so we're doing well; swimming about and such, and the remainder were all doing the 'death spiral' (swimming in tight circles, .25 to 1 in circles up towards the light, then sinking to the bottom of the tank head first). Eventually, everyone started doing this, and I thought it may be due to the krylon fusion paint I was using in the kreisel, and that is why everyone who was still alive was moved to the 2.5 (it was all that I had immediately on hand). They seemed to recover, and began swimming normally around the tank. Fast forward to about 6 tonight, the last of my ocellaris larvae have given up the ghost.

I found it strange, and honestly very frustrating, to see a 100% mortality in 24 hours, especially because I've always thought that the death spiral was due to starvation. The things I think might be causing this are:

-my greenwater. I'm using rotigrow one step for my cultures and tank greening. I know that using rotigrow in the rearing tank isn't recommended, but I wouldn't think it would kill them. At least not that soon.

-the krylon fusion possibly leaching chemicals into the water larvae army able to handle

- broodstock diet: they eat mostly Frozen mysis, brine, cyclopeeze, and various Hikary pellets. Is too much frozen food a thing?

- collection method: is the Vossen trap possibly to rough on them? I have the air flow as low as it can be without them being able to swim straight out the entrance. Egg transfer isn't an option, the pair is in a reef display.

- possible bacteria in broodstock water?

Water parimiters are good, ammonia 0, nitrites 0, nitrates are detectable, bit still acceptable.

Has anyone experienced the 'death spiral' before? If so, what caused it?

Stay tuned for more stupid questions from yours truly! :P

01/30/2016, 03:27 AM
1st off why are you painting the inside of the tank with krylon? why not the outside? do you have pics of the setup?

you say they are at the bottom of the tank doing head stands, that is a sign of to bright of light.

what are you useing for a heater and air?

the food for the brodstock looks good but the brine could go unless your enriching it with something first.

how long did you let the paint dry before useing water in it?

i've never used rotigrow so can't help you there. i have always used rgcomplete.

01/30/2016, 11:08 AM

The kreisel body is made of formed acrylic, so the outer side being painted is exposed to the water in the equipment chamber. Heat is a 50w hydor heater set to 81, air is a single airstone a few inches below the surface of the water n the kreisel chamber. As for lighting, I'm using a 9w full spectrum cfl mounted a couple of inches above the tank. (about 5 inches from water surface) for the first several hours, I dim the light with frosted plastic sheets, and slowly remove them as they grow accustomed to the light.
The kreisel was something I built several months ago, and it sat in my garage unused for several months. So I'm sure the paint is fully cured.

They aren't head standing on the bottom; they spiral to the surface, than sink to the bottom, usually head first. As soon as the hit the bottom, begin spiraling to the surface again.

Do you use rgcomplete for green water?

Thanks for your help!

01/30/2016, 01:47 PM

Here is a pic of the system with no water in it.

01/31/2016, 09:32 AM
i would put the air stone at the bottom, you will get much better o2 in the tank.

if the paint is on the outside then that water wont be in contact with the water on the inside of the krissel right? if so then the paint wont be an issue.

yes i use rgcomplete for greenwater

01/31/2016, 11:01 AM
I would lose the kreisel, you don't need it. Paint the outside of the tank. Better oxygen interaction and absorption. Reduce the lighting. Of you can save the picture, it's from Joyce Wilkersons book.

01/31/2016, 12:39 PM
How often and how much are feeding the broodstock? (too much isn't a problem, so long as water quality remains good).

01/31/2016, 02:40 PM
So now I'm really beating myself up, oxygen was something I completely overlooked. The larvae always make it through the first night with near 0% mortality, but once rotis are added, then they start dropping. I'm gonna lower the airstone like you said, Shifty, and add a wooden air diffuser in the equipment chamber. I'll also try raising the light.

02/01/2016, 10:42 AM
I use RG complete as well. I use it to feed the rotifer bucket, and to tint the fry tank a little green.

I put the rotifers in the nursery tank the same night I put the newly hatched fry in, and I've got the airstone going pretty briskly. I put the airstone under the heater, to circulate the warmed water and to keep them off the heater. So they don't fry themselves.

02/01/2016, 10:47 AM



02/02/2016, 11:14 AM
in a 10g tank with 6" water from dt add green water and rotifers heater on its side air stone under with very light amount of bubbles. i add larval as soon has i see a good number in the trap it takes 3 or so times to get all the larval caught. has for light i put a sheet of paper in front of the lamp to diffuse the light.

02/23/2016, 01:56 PM
Hey, just thought I would share a little update:For my next batch I ditched the kreisel, turned up the airstone, and dramatically reduced lighting for the first couple of days. Right now I have 19 juvis 14 dph
It's not the greatest number, but I'm happy to see a little success.

02/23/2016, 09:57 PM
Congrats, its a start

02/27/2016, 08:39 PM
So they don't fry themselves.

Very Punny LOL

04/14/2016, 09:28 AM
Nice photo too!

How did you get such a great pic?

04/19/2016, 07:44 PM
Nice photo too!

How did you get such a great pic?

Actually just with my iPhone and one of those clip on macro lenses.
The hardest part was that with the lens in, the phone had a very small focal range, so the fish had to be in just the right spot for the camera to focus.