Cycling question

[Chrisrex]

I know that this has probably been asked but just want to ask peoples current view on water changes during cycling of a new tank.

Personally I’m cycling
29gal biocube oceanic
20 pounds of dry rock
25 pounds of live sand
Mp10w pump
Mj1200 return pump
Intank media basket with filter floss/Purgen/chemi-pure elite
Tunze 9002 skimmer with upgraded mj600 pump
Also running a AI Sol blue led fixture
H2ocean salt mix
BRS 5 stage RO/Di tds is reading 0tds

Again wondering what peoples thoughts are on water changes and recommendations

[WarDog]

Wait until nitrite spikes, then drops to 0, and then do your first w/c of 50%.

[Myka]

I don't do water changes in new tanks until there is a reason. Usually on new tanks (especially those with Marco rock or other sterile-type dry rock) there is barely a whiff of nitrate after the cycle is over, so the first water change will be 4-6 weeks after the initial cycle is over. Then monthly-ish water changes. As the population of corals increases then the water changes become more often. If there is no nitrate or a tiny amount present there is no reason to do a water change. There won't be a significant number of corals in the tank using up trace elements so doing a water change is a waste of time. I just mix around the sand once or twice a week with a set of long tweezers/tongs to keep it aerated. New tanks started with clean, dry rock need to be "dirtied up" a bit - they are sterile, wasteland until some life gets introduced. I always add a big, gross, dirty filter pad from a HEALTHY established reef to a new tank to introduce some bacteria strains and microfauna like various species of copepods and amphipods once the cycle is complete.


On the other hand, some tanks have horrendous amounts of nitrate after the initial cycle because the rock is super dirty or the person added a whack of food/shrimp to initiate the cycle and totally overdid it. In that case, I'd do a 50-100% water change to flush some of that crap out. If I see a ton of ammonia and/or nitrite forming (say more than 3 ppm) then I'll do a large water change mid-cycle. I won't add the dirty filter pad until the cycle is complete and nitrate is under 10 ppm.


It's all about the nutrients...too much organics and big water changes, no organics, no water changes.

[DKoKoMan]

Very well explained