Cycling Tank - Water Test Questions

[dankoos]

Ok, tank has been cycling for almost a week..90 gallon FOWLR tank. Day 1, added 50 lbs cured live rock (from local source, yes i plan to add more later..fully cured from same source). Day 3, added two raw shrimp. Day 5, tested and got the following readings:

Am = .25
Nitrite = 0

Day 7:

Am = .50
Nitrite = 0
Nitrate = 0
Ph = 7.8

Day 9:

Am = .50
Nitrite = 0

I have not been testing for nitrate every time...that doesn't show up until after you start having nitrite, correct?

Also, when should I expect Nitrite to start showing up?

[Michael]

as the rock was fully cured you may not see any nitrite at all, in fact im suprised your seeing ammonia, the rock should have enough beneficial bacteria already on it to deal with the shrimp, perhaps theres a little die off.

[dankoos]

So if that is the case, when is it safe to add fish? When the ammonia I do have goes back down to zero?

[stingythingy45]

Originally Posted by Michael

as the rock was fully cured you may not see any nitrite at all, in fact im suprised your seeing ammonia, the rock should have enough beneficial bacteria already on it to deal with the shrimp, perhaps theres a little die off.

I agree,if the rock truly had a "robust" bacteria colony then ammonia would be just slightly detectable and diminish fast.
In any case,you're doing the correct thing by testing and getting a reliable bacteria colony present in the tank.

[Michael]

wait for now, just in case the rock wasnt cured and it needs to cycle, patience will help you long term.

[stingythingy45]

Originally Posted by dankoos

So if that is the case, when is it safe to add fish? When the ammonia I do have goes back down to zero?

Yup,ammonia down to zero.
Do about a 20% water change then add CUC first.
See how they do for a week.Then add a fish or two,no more than that.
Wait and test to make sure things remain ok.
Add things slowly over weeks time.Every time you add a fish the bacteria colony will re-adjust in the tank.

[IslandCrow]

I'd add to the above post to give yourself at least a week with 0 ammonia before adding anything. It's not unheard of for ammonia to drop to zero, only to rise slightly a few days later.

[dankoos]

Great thanks...have been reading and seeing the advice of doing a water change after the cycle. In my case, I have about 75 or so of the 90 gallons in the tank now. I have a 55 gallon sump that is not yet set up because I am waiting on my backordered skimmer. Once the cycle is done and I add water to the sump and top off the DT, will that serve as a "water change"?

[stingythingy45]

Originally Posted by dankoos

Great thanks...have been reading and seeing the advice of doing a water change after the cycle. In my case, I have about 75 or so of the 90 gallons in the tank now. I have a 55 gallon sump that is not yet set up because I am waiting on my backordered skimmer. Once the cycle is done and I add water to the sump and top off the DT, will that serve as a "water change"?

Well,it is dilution of the pollution,so that will work.Most folks do a water change to drop nitrates and start somewhat fresh before adding live stock.
Very true what IslandCrow stated about having steady non-ammonia readings for a week.Also,when in doubt test twice.

[dankoos]

I love it..."dillution of the pollution"

[orion1]

I would also wait until you get the sump and skimmer online and no ammonia readings before adding any livestock

[dankoos]

Originally Posted by orion1

I would also wait until you get the sump and skimmer online and no ammonia readings before adding any livestock

Absolutely...didn't plan on it. Figured I will have sump up and running before cycle is over anyway.

[Michael]

a sump and skimmer wont affect the tank regarding livestock, although i would never run a reef tank without a skimmer, it is not essential, to me yes but many reefers manage without one, and a sump is convenient but not essential at all, ensuring the media has cycled and ammonia 0 is important.

[wooden_reefer]

Originally Posted by dankoos

Ok, tank has been cycling for almost a week..90 gallon FOWLR tank. Day 1, added 50 lbs cured live rock (from local source, yes i plan to add more later..fully cured from same source). Day 3, added two raw shrimp. Day 5, tested and got the following readings:

Am = .25
Nitrite = 0

Day 7:

Am = .50
Nitrite = 0
Nitrate = 0
Ph = 7.8

Day 9:

Am = .50
Nitrite = 0

I have not been testing for nitrate every time...that doesn't show up until after you start having nitrite, correct?

Also, when should I expect Nitrite to start showing up?

You do not always have nitrite. If you have enough nitrobacter in medium, all nitrite will be immediately converted to nitrate.

Sometimes, like cycling with dead rock without any lives to save, you can add a strong pulse of ammonia to confirm rigorously the presence of nitrobacter. There will always be a strong enough pulse of ammonia to ensure the appearance of nitrite; 5 ppm ammonia will generate nitrite, almost always, even with a well-cycled medium.

Do not add a strong pulse of ammonia if you have lives to save on LR.

I think you are OK if you continue to have significant ammonia for the first half of the cycle.

[dankoos]

Well, I believe my first official mistake was to put the nice cured live rock into water that just came from the RO system...w/o warming it. Some worms came crawling out of the rock, but appear to be dead...figuring that was due to the temperature shock..probably took heater a day or so to get things up to temperature. Also noticed a dead pod or two...other than that, do not see any life..besides some coraline and some tiny green bubble things of some sort. Not in any hurry, would rather not add straight ammonia if I can help it.

[wooden_reefer]

Originally Posted by dankoos

Well, I believe my first official mistake was to put the nice cured live rock into water that just came from the RO system...w/o warming it.

What about salinity? Did you match salinity before placing the live rock?

If you want to be very sure even just for peace of mind, you can make sure that there has been nitrite during the cycle. Nitrite coming and then going is the rigorous proof.

Could you have killed off all nitrification bacteria from the rock? I doubt very much.

[dankoos]

Yes, did add salt to the RO water...tested it until it was the accepted level, then added it to tank, then added rock.

[Michael]

there is no problem here, just allow the tank to sit for a few days and test for ammonia, with the shrimp in the tank it will get stronger if the rock cant support beneficial bacteria at this time, if the ammonia level disappears then the tank is doing fine, as mentioned before, patience is important at this time.

[wooden_reefer]

Originally Posted by dankoos

Yes, did add salt to the RO water...tested it until it was the accepted level, then added it to tank, then added rock.

Going from 75F to 55F likely will not kill all nitrification bacteria.

I think you are OK if you continue to have some ammonia, even just 0.5 ppm, for the first half of the cycle.

There is a difference between can be OK and confirmed to be OK.

If the rock is already cycled, you can have 0,0 and nitrate should increase if denitrification is not yet significant.