Adding too much bacteria into the pond is not great. But, it’s also not catastrophic.
Bacteria works to break down debris, muck and stuff in the water. (Stuff is a technical pond term). As it consumes these things that would otherwise be nutrients for algae, it is helping keep the water clean.
Know your pond
It’s a good practice to know the number of gallons in your pond so that when you need to add bacteria or dechlorinator, you can easily follow the instructions on the product to use the right amount.
Bacteria die off
If a large amount of bacteria are accidentally introduced into the pond, it will not kill the fish.
What it will do is circulate through your pond with the water and break down elements (stuff) down more quickly than normal. Not leaves or giant debris but the microscopic things that bacteria breaks down . (I’m not a scientist! lol!) You might see a build up of foam from this.
If the bacteria consumes all the microscopically available nutrition, it might die off. Leaving the pond without bacteria in a few days. This can ironically lead to nutrients building up and (can you see it coming?) an ALGAE OUTBREAK!
What to do about too much bacteria into the pond
So, if you accidentally dump a bunch of bacteria into your pond, sit tight and add the recommended dosage to the pond in 3 or 4 days. Then add bacteria at the normal dosage again once a week. All will be well.
If you are one of those people that adds bacteria consistently for about 6 weeks and then sort of trails off and forgets to do it for weeks at a time, consider putting in an automatic dosing system. I love these things because the slowly dose the pond with good bacteria slowly land consistently without any human having to remember!
Want to learn more about bacteria? Click HERE for more information.