Infusoria culture question

[Johnny B. Goode]

I recently made my first infusoria culture. I used tank water, a piece of hornwort and a piece of acorn squash. It just cleared up and all I can say is, WOW! It is so cool to draw that water up in a pipette and see all the micro minis in there moving all around. Anyway, I am attempting to breed bolivian rams and orange laser corys so that is why I made the culture. My question is how long do I have before the culture needs to be "refreshed" as far as taking out the old piece of squash for a new one or even new water?

[gardenman]

As is often the case, it depends. Water quality for the infusoria will be the same type of issues we have in aquariums. If the water goes bad, the infusoria will die. The hornwort will help to keep the water a bit more stable by absorbing some of the waste. Starting a backup culture or two is always wise if you're going to be dependent on the infusoria to feed your fish. Then you can push things a bit in your first culture and see if/when it crashes. If the culture crashes ten days after you put in the  squash, then try replacing the squash and doing a water change on day seven in culture two. If that works then you know how frequently to change the water and replace the food. Multiple small cultures are typically better than one big one. It gives you some insurance and some food for your fry no matter what happens. 

[Johnny B. Goode]

Awesome! Thank you for the information. I'm going to grab some jars tomorrow and start a couple more.

[Hobbit]

I agree with @gardenman! I will say, I find my infusoria cultures last basically indefinitely, though there seems to be a few days where the culture “booms” and after that the number of desirable microorganisms starts to go down. Though I almost always use up the culture before it goes bad—it’s surprising how quickly you can go through one when you’re feeding small amounts throughout the day! So having backup cultures is a good idea for multiple reasons.

I use exclusively lettuce/spinach/leaves in my cultures, so I’m not sure how the food you feed affects how long the culture lasts.