Why do the alevin stay under rocks?
This is a natural behavior. The gravel provides cover from predators and the river current. In the wild, salmon emerge from the gravel in search of food after the yolk sac has been absorbed.
What do I do if I notice fungus on the bottom of the tank?
Carefully remove the rocks from the incubator, one at a time (only if all the eggs have hatched), using a pair of tongs. Vacuum the fungus off the bottom of the tank using the gravity fed siphon and replace the volume withdrawn with clean water. Clean the filter sponge element and replace the activated carbon and/or ammonia filter elements as necessary. Clean the sponge on the intake tube.
What happens if I notice changes in water color and odor?
If the water begins to smell and/or changes color, there are definite water quality problems - probably due to high ammonia levels. Make water changes (as outlined in the housekeeping page) until the water remains clear and the odor disappears. Replace the zeolite clay (ammonia removing) filter element.
What happens if my tank leaks?
Some tanks seem to develop small leaks after a period of time. Unless the leak is unmanageable (beyond the drip stage) it is better to live with it until the salmon are released. If the leak is severe then the fish will have to be transferred to another tank. A leaking tank can be resealed using silicone made specifically for aquariums. Standard off-the-shelf silicone sealant contains chemicals that will harm the fish.
Why are some of the eggs turning white?
Eggs that turn white are dead. A certain number of dead eggs should be expected in every salmon family. That's normal. Dead eggs should be removed promptly using an egg picker or turkey baster. Fungus may soon appear if dead eggs are not removed and will endanger the remaining live eggs.
The chiller is not maintaining the proper temperature. What should I do?
Some of the refrigerant in the chiller may have leaked out or the thermostat may not be working properly. The chiller needs to be repaired.
What do I do if the chiller breaks down?
If the chiller breaks down after the eggs have hatched all is not necessarily lost. Alevin and fry have proven to be viable in room temperature water - the cooler, the better. If the chiller breaks down with eggs in the incubator, move the eggs to a glass container placed in a refrigerator. If possible, this water should be aerated and/or filtered (refer to Option B incubator instructions).
How can I tell when the salmon/trout are ready to feed?
When the salmon are ready to feed, they will emerge from the gravel and swim up into the water column. This is the cue to start to them on feed. There is a limited window of opportunity, beyond which the salmon/trout will no longer be able to "learn" how to feed. Fish that don't learn to feed eventually become "pin heads" due to a large head and undernourished body. These fish will die.
Can I look at eggs and alevin under a microscope?
Yes, students will enjoy looking at the various developmental stages under a microscope. A video microscope is even better. The "critter" should be placed in a water filled petri dish and not kept out of the incubator for more than a couple of minutes. A cool light source is best for use with the microscope.
What happens if the salesperson at the aquarium store recommends that I purchase equipment that is different from what is called for in this guide?
Aquarium store employees can be very knowledgeable and usually mean well. However, their knowledge is usually limited to tropical fish. Disregard their recommendations and follow this guide.
If I am having water quality problems in my incubator, will any of the fish medications or chemicals available at aquarium stores solve my problems?
No, do not add any chemicals to the salmon incubator. The only thing that will successfully address water quality problems is water replacement and filtration.
Do I always have to dechlorinate water before adding it to the incubator, even if I know it comes from a well?
Unless you are absolutely certain that there is no chlorine in the water, it shoud be treated as if it did. The water can be left standing in the open air for 72 hours and/or treated with a chlorine neutralizing chemical (available at most aquarium stores).
My fish were doing fine and then, all of a sudden, they all died within a few days. What happened?
Ammonia levels in the tank were probably too high. The die off could also have been the result of fungus or bacterial gill disease. All three are the result of poor water quality.
The chiller coil in my incubator is icing up. How do I fix this?
The chiller thermostat is set too low (shouldn't be set below 36 degrees Fahrenheit) and/or there is insufficient water movement within the tank. The filter size (too small) and or location (on the short side of the tank) within the tank may be causing the inadequate flow. Place air stones below the chiller coil to increase water movement. Move the filter to a new location within the tank and/or consider replacing the filter with a larger model. Raise the chiller temperature setting.
When can I remove the foam panels from around the aquarium?
The foam panels can be removed about one month before the scheduled release date. The tank should be placed in an area with indirect lighting.
Do I have to feed the salmon while they are in the classroom?
The answer is a qualified "no." If the water temperature in the incubator is kept in the forty degree range until just before the scheduled release date (in May or early June), chances are that the salmon/trout fry will still have yolk sacs; they'll still be alevin. Releasing alevin (which are technically unfed fry) is perfectly acceptable. Keep in mind that the incubator water will have to be at about the same temperature as the stream by release day. Adjusting the water temperatures from forty to fifty-five degrees will take awhile (about five degrees per day).