For my 50g with 20g sump i was given a plastic cup full of chaeto, it droped my nitrates from 10 to 5. Then i got another cup full and it dropped it to zero. Im not sure if the second cup made a difference but i keep that amount in my sump. If you get a large size taco bell cup and fill it with chato (do not pack it), then that would be equivalent to my two cups. It grows very quicky, i now cut it and keep the taco bell cup amount in my sump and give the rest away.
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