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Pre cycle a filter to avoid diatoms in a new tank?

935 Views 3 Replies 4 Participants Last post by  SueD
I plan to start a 20L or 29 gallon in March. I may or may not go emersed to grow in a carpet of HC. I would hate to go through all that work if I do only to have diatoms nail me a month after I flood the tank. Sure most of the time it is temporary but if I can avoid it I would like to.

While I am letting the HC grow in, I thought I could set up a 10 gallon in my garage with the filter and perform a fishless cycle with ammonia. Then, when I flood the tank, the filter and media are already charged and ready. I have read a few threads online and feel it should be easy enough. I have an API kit to monitor readings.

Will this prevent diatoms or does that just happen while everything balances anyway?
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I have moved cycled filters/media to new tanks and still had the diatom bloom. So for me, no, it didn't help at all. That's my experience though. I recently moved cherry shrimp to a new and larger home that had quite a bit of diatoms and they were all gone in just a few days. The diatoms, that is. The cherries were all lounging around with toothpicks hanging from their mouths.
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I don't know if it will help. When I moved everything from my old 20L into my current 38gal, I transferred everything- substrate, plants, hardscape, all the established filter media into the new filter. I got a pretty much an 'instant cycle' but still had diatoms for weeks- until I figured out how to balance the light/ferts/fish load/everything.
I also set up a tank using a cycled filter in a well planted tank and got plenty of diatoms which eventually disappeared. I think the diatoms are a result of the silica in the substrate and once that has all dissipated, the diatoms will be gone.
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