(This page is a work in progress. Feel free to contribute your own best practices. Send an email to email@example.com. Thanks! -Mike)
RULE # 1 – You will get out of it what you put into it. Yes it takes some effort to get moving, but once you dial in your program you too will be running your own sustainable gambusia program. If you’re just getting started, consider having just one or two people focused on the operations. You’ll have better insight into what works and what doesn’t, how your fish respond to different environmental factors like water temperature, feeding schedules and lighting conditions. And as you develop your program, don’t forget to document the results! You will have evidence of successes and failures and be able to fine tune your operations as needed. Our most successful customers use a cycle of Change > Collect Data > Evaluate Results > Repeat.
The information below is a collection of information provided by our customers based on their own experiences. If you find something that works, please share it with us at firstname.lastname@example.org. And please share if you find something that doesn’t work too, that information is just as helpful. Thank you to our community of customers!
- Initial Water Quality – Your water quality is a key aspect in the success of your gambusia operations. If you’re just getting started, take a water sample from your input source (city water, well, etc.) and have it professionally tested. Then you’ll know what you’re dealing with when it comes to balancing our the pH, alkalinity, nitrates, etc.
- If you have a city water source, you need to be alert to the hazard of introducing chlorine or chloramine into your tanks. Consider installing a carbon filter inline with your water supply before introducing water to your tanks. We can help you make that determination during the design process.
- Maintaining Water Quality – Sometimes it can be challenge to maintain your water quality at levels that keep the fish healthy and reproducing. But remember, although the solution is set up as a controlled environment to make things consistent and easy to use, that’s not the type of environment the fish would be used to in the wild. You may get some algae in your tanks. Your water might not be perfectly clear. Don’t panic, as long as it isn’t detrimental to the fish or system components (example: some algae is ok, but string algae is No Bueno!), consider it part of the ecosystem. So what should I be monitoring in my water quality?
- Alkalinity 90-120 ppm
- pH 7.5-8
- Is there such a thing as having too high an alkalinity reading? YES! Alkalinity is not an exact science, but it does need to stay in the ‘normal’ range shown above. If your alkalinity gets too high, it can affect fish health and potentially shorten the lifespan of some equipment.
Breeding & Grow Out
- Use full length tanks (no dividers) for your breeding tank.
- Use 1 year old stock for breeding, but no more than 3 years old
- Tank density recommendation: Between 10-20 lbs of 1 year old stock seems to be a good balance between fry production and minimizing loss from adult cannibalism (1 pound of 1 year old stock is approximately 850 fish)
- Tank coverage – Target 50% surface coverage. About 3 birthing boxes in a full size tank should maximize survival rates of the fry. If there is only one birthing box in the tank, your fry survival rates tend to be lower due to cannibalism. Essentially with a single birthing box, the adults know where to find an extra meal if they are hungry. But with a higher surface coverage, the females have a more space to deliver and the fry have more protection.
- Water temperature can drastically effect fry production and growth. Target 84 degrees and adjust as needed for your climate.
- Fry Collection – at least twice per day
- Grow out separation – group your fry in 1-2 week lifecycle increments for the best survival rates. A fast growing 3 week old fry can eat up a newbie easily.
- Wintering – If your production schedule allows, use the winter months to give the female gambusia a break. Try to work in a 2 month slow/non-production period.
- What kind of food should I be using? Most of our customers are using feed blends from either Zeigler or Star Milling.
- Want to control the mixture yourself? Some customers have recommended a blend of salmon meal, spirulina powder and Hikari plankton.
- Feel free to contact us and we would be happy to get you in touch with feed suppliers.