We are having problems with our embryos and I was wondering if you could possibly point me in the right direction.
The fishes we are using to breed are <1 year old (including the ones that you just sent us a few weeks ago) with most of them being between 6-8 months of age. Up until about a week ago, we were getting fairly decent clutches with normal development. Recently, though, the development of the embryos has been highly irregular. They are either laid as small and opaque, or they appear normal to the naked eye, but when they are placed under a microscope it becomes apparent that the cell division is highly uneven (ie one side is much larger than the other). This has been occurring on both of our systems (housed in the same room about 3 feet apart). Death occurs to approximately 90% of all embryos.
The water quality parameters have been averaging the following:
pH 6.9- 7.1
Conductivity 450- 520
Alkalinity 17.1 mg/L
Carbon Dioxide 8 mg/L
Cl ion 180 mg/L
Ammonia 0 mg/L
Oxygen 10 mg/L
Nitrite 0 mg/L
Hardness 119 mg/L (though this has been a little elevated lately)
I am doing a 10% water change daily, except for the weekends. To make my fishwater, I usually add about 175 ml of concentrated Instant Ocean (20 g/L) per 20L of ddWater. This varies a little depending on the conductivity measurement. Also, I am using the carbonite method of water buffering that we discussed previously.
As for feeding, I am feeding freshly hatched brineshrimp 2X per day (morning and afternoon) as well as feeding them with the Master Mix that ZIRC uses (I don't use the cyclopeeze in this, but otherwise it's identical to the recipe that you sent me).
Anyway, that's all that I can think of for right now. If you see any flaw in my protocol, I'd be open to suggestions.
Thanks in advance for all of your help