Water parameters changing

[Mr31415]

My water parameters after adding live rock and letting it stabalise were (new startup):

pH: 8.18
Temp: 24.5C
Alkalinity: 6.0 (dKH)
SG: 1.025

Ammonia/Nitrites/Nitrates: Measured by shop and said not a problem.

That was 1 July. I added that same day one smallish Colt Coral, one mushroom coral, a Boxer Shrimp, 4 Turbo snails and 4 blue legged Hermit crabs - i.e. the first live stock (non-live rock).

Today (4 July) I measured again. The parameters are:

pH: 8.00 (Less accurate test kit so it could just as well be 8.18)
Temp: 25C
Alkalinity: 5.0 (dKH)
SG: 1.026
Ammonia: 0.01mg/l
Nitrite: 0.20mg/l
Nitrate: 10mg/l

My questions are:

1) Why does my alkalinity drop so much? I have been adding RO topup water using a Tunze Calcium Dispenser with Kalkwasser since 29 June.
2) Is the low Alkalinity value a serious problem even though the pH is constant?
3) It seems as if I am in the second phase of the Nitrogen Cycle - am I right? Where ammonia is been broken down and nitrite bacteria is growing to handle the load?

[sir_dudeguy]

cant really answer the questions but why'd you add corals right awya? and you need to either get ur own tests, or find out the numbers of the amonia nitrite and nitrate...the lfs can say "they're good" but not know what the crap they're talkin about...more often than not, they dont know much anymore

if you dont know these numbers you dont know if its even cycling

[Mr31415]

<a href=showthread.php?s=&postid=7679592#post7679592 target=_blank>Originally posted</a> by sir_dudeguy
cant really answer the questions but why'd you add corals right awya? and you need to either get ur own tests, or find out the numbers of the amonia nitrite and nitrate...the lfs can say "they're good" but not know what the crap they're talkin about...more often than not, they dont know much anymore

if you dont know these numbers you dont know if its even cycling

I asked the LFS what invertebrates are good to start with, and they suggested the cleanup crew I mentioned as well as a hardy coral such as the Colt Coral.

Since I had cured live rock which did not show any spike in Ammonia or Nitrites I guess they assumed the water was OK.

I must say - usually I would agree 100% that they do not know anything. However in this case the LFS is the most recognised in our country - so much so that their people regularly go overseas and have regular contact with people like Julian Sprung etc. And I saw the test being done - the parameters were indeed very low.

[sir_dudeguy]

what lfs is this? they need to make one here in az lol.

anyways...since it was cured live rock, there shouldnt be anything to worry about, but i still woulda waited about 3 days just to make sure. sometimes there can still be some die off. and did the lfs even test for the stuff? or did they just so "ok since its cured ur fine"?

[bertoni]

1) Alkalinity can be consumed very rapidly by coral and coralline algae. That drop isn't that bad.

2) Corals and coralline algae won't be able to grow with that level. I maintain mine at around 9-10 dKH.

3) That sounds about right, although tanks that have live rock can go through a lot of patterns, not just the ones that get writeups.

[Mr31415]

Well I waited 4 days since adding the live rock and adding the invertebrates. I am not sure whether the LFS tested the rock - I did however go through each piece as I gave it a rinse under my seawater and did not find anything obvious. While the rock were in my tank I also did not detect anything funny - i.e. ammonia levels were undetectable the whole time.

The LFS is Exotic Aquariums.

[Mr31415]

<a href=showthread.php?s=&postid=7679948#post7679948 target=_blank>Originally posted</a> by bertoni
1) Alkalinity can be consumed very rapidly by coral and coralline algae. That drop isn't that bad.

2) Corals and coralline algae won't be able to grow with that level. I maintain mine at around 9-10 dKH.

3) That sounds about right, although tanks that have live rock can go through a lot of patterns, not just the ones that get writeups.

Thanks for the reply. I cannot see any algae in my tank - and I only have the one Colt Corel and one mushroom in my tank. The tank is 550l. Can those two corals and no (visible) algae be able to consume that much alkalinity?

Is it sufficient to use the kalkwasser doser to get the alkalinity up? Or is there another way? The kalkwasser doser I have is one connected to my Tunze topup unit that just pumps the clean RO topup water through the tube containing the kalkwasser/water mix into the sump.

[bertoni]

Hmm, I'd guess something's consuming it. I wouldn't worry all that much yet.

Limewater often has too high a pH to be useful for raising alkalinity and calcium more than small amounts. Some baking soda and a calcium chloride product, like Turbo Calcium or bulk Dow Flake will work for that. Then use the limewater to keep alkalinity and Ca in line. This article discusses dosing lime in detail:

http://www.reefkeeping.com/issues/2005-01/rhf/index.php