Hello,
I would never go beyond 25% (abs. max 30%) unless there were a real emergency. Only the ammonia level is of concern, and if it rises any further I would be inclined to deploy zeolite (in onion sacks), initially swapping sacks over every day and flushing the 'used' sack in saline for 24 hours, then rinsing it very thoroughly before re-deploying -- I might even consider that were my ammonia to reach just 0.5%.


Thanks.

I didn't find the right solution from the internet.

References:

- https://www.pond-life.me.uk/forum/viewtopic.php?f=27&t=15349

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