100% water change= re-cycle tank?

lazycouch · Mar 8, 2021

hello everyone. just did a 100% water change + cleaned the sand quite deeply after neglecting this tank for a bit. it’s 7 months old and the rock i purchased was live from a hobbyist, safe to say it was seeded for 1yr+ for sure. i plan on adding a lionfish in here but was wondering how long it’d take to know if i have to re-cycle the tank tested in 24hrs but theres no source of ammonia or nitrites atm and i prefer not to dump pure ammonia to double check since i still have my urchin in there so i’ve dosed bacteria and prime for now just in case.. what do you think? is it safe to add a lionfish considering the live rock + biomedia + liverock rubble in the sump.. would removing 100% of the water and messing with the sand be enough to restart the cycle? thanks for any input to whoever bothered to read this lol

brandon429 · Mar 8, 2021

It’s fine to reef with now, any ammonia events from the sand are passed in an hour after disturbance.

the firmest rule in cycling is that no degree of water change or cleaning harms your filter bac, that’s a beneficial rule for this post

in my opinion I own a reef tank thats had more 100% water changes than any reef owned. It’s a pico reef packed with corals for fifteen years and water changes are 100% every week or so, that long. Sometimes I don’t even rush to refill it while drained, can go up to 30 mins wait in the air now. What you did was far nicer to the surfaces

the temporary cycle from deep cleaning comes from kicking up waste that overcomes bacteria temporarily its not because cleaning removed them

so that means if someone has a live rock only setup, no sand, that doesn’t hold much waste you can change the water as often and as fully as you like. But with old sandbeds, every water change kicks up new waste and it circulates around various stages of rot, until that settles it can contain irritants.

lazycouch · Mar 8, 2021

brandon429 said:
It’s fine to reef with now, any ammonia events from the sand are passed in an hour after disturbance.

the firmest rule in cycling is that no degree of water change or cleaning harms your filter bac, that’s a beneficial rule for this post

in my opinion I own a reef tank thats had more 100% water changes than any reef owned. It’s a pico reef packed with corals for fifteen years and water changes are 100% every week or so, that long. Sometimes I don’t even rush to refill it while drained, can go up to 30 mins wait in the air now. What you did was far nicer to the surfaces

the temporary cycle from deep cleaning comes from kicking up waste that overcomes bacteria temporarily its not because cleaning removed them

so that means if someone has a live rock only setup, no sand, that doesn’t hold much waste you can change the water as often and as fully as you like. But with old sandbeds, every water change kicks up new waste and it circulates around various stages of rot, until that settles it can contain irritants.

thanks for the info ! i also forgot to add that there had been a school of zebra damsels in there up until yesterday so maybe the bacteria has had enough time to multiply.. would you the. say it’s safe to add a lionfish yet?