Help. My alk is dropping fast!

[pdnyc69]

My alk is going from 10dkh at nite to 8dkh by morning. Some of my acans are taking a beating but everything else looks good. I have clams zoas acans palys some leathers. 4 of my acan colonies are not expanding and my 2 brains are not expanding. Does anyone know what could be causing this?

 

[pecan2phat]

Are you using a Calcium reactor? If so, you need to slowly adjust the drip rate & bubble per minute to match your uptake needs of the tank.

8 DKH should not be critical. Natural Seawater levels are at about 8 DKH but we tend to keep it higher to stablize the PH. I've had my Alk drop down into the 6's when I neglect to test for months without seeing any real damage to the corals.

 

[pdnyc69]

I'm using a kalk reactor. Do I need more kalkawasser in my reactor?

 

[pdnyc69]

Also minutes after I add alk my acans begin to puff up almost back to normal but the brains stay shrunk.

 

[SevTT]

My alk is going from 10dkh at nite to 8dkh by morning. Some of my acans are taking a beating but everything else looks good. I have clams zoas acans palys some leathers. 4 of my acan colonies are not expanding and my 2 brains are not expanding. Does anyone know what could be causing this?

Do you have a relatively small, moderately stocked tank? If so is normal. It's partially due to the pH drop / CO2 increase at night, combined with lower evaporation causing your kalk system to top off less, and partially due to the fact that most stony corals do most of their calcification at night.

Running a macroalgae fuge can help. I've also had great results increasing my alk/pH stability by buffering my kalkwasser with vinegar. (I don't have a reactor, I just mix 5 gal water, a tablespoon of vinegar, and 7 tsp kalk and stick my ATO on it.)

 

[jackson6745]

I agree with SevTT. It is normal to have your alk swing a little from morning to night.
Pete I have a tank full of SPS and my alk swings all over the place with no ill effects to corals. I would think your problem with more hardy acans lies somewhere else.

 

[pdnyc69]

My nitrite, nitrate, ammonia, phos is all zero. I have a fuge running with chaeto with the light on at nite time. I have had this tank like this for a while with no crazy swings. I have a lot of corals. Only 1 sps. The rest are all lps. At first I thought the problem might have been the addition of gfo to my system as the problem started around then (2 weeks ago). I have since removed the gfo out of the reactor. Also I don't use co with my kalk reactor. It is a stirrer used with the ato.

 

[tomtoothdoc]

check your mag. i had an alk. drop and it turned out my mag. was low. once the mag. was boosted and additional alk. (i use brs 2 parts on dosers) was adjusted, it's stable again.

 

[SevTT]

check your mag. i had an alk. drop and it turned out my mag. was low. once the mag. was boosted and additional alk. (i use brs 2 parts on dosers) was adjusted, it's stable again.

Oh, duh, yeah, this too. +1

 

[pecan2phat]

I think that using kalk only for a large tank is difficult to keep Alkalinity stable without causing Calcium to be in the 500 ppm + range.
I would just monitor and add Seachem Reef Builder every week.

 

[pdnyc69]

My mag is 1500 and calcium is 600.

 

[tomtoothdoc]

My mag is 1500 and calcium is 600.

i'm sure you're already aware the cal. is kinda high....the numbers don't seem to make sense. what are your normal alk and cal. # before all this?
my alk and cal. # seem to go up and down proportionately. but i've never use a kalk. reactor....just out of curiosity what is your ph at the time you test these parameters.? when do you measure them...in relation to your photo period? btw what is your total volume?

 

[pdnyc69]

My total water volume is 250 gallons. I test morning and night. Ph stays at 8.3. My cal has always been high. Alk was 9.5 ish. Mag has always been 1500 ish. I just don't know what happened.

 

[tomtoothdoc]

My total water volume is 250 gallons. I test morning and night. Ph stays at 8.3. My cal has always been high. Alk was 9.5 ish. Mag has always been 1500 ish. I just don't know what happened.

i'm stumped....alk. may fluctuates.... but 2 whole pts. from light to dark period?....does the ph fluctuate with the alk.?
when does the ato pumps in the kalk.? do you have it on a timer? perhaps you happened to test right after the top off....the reading may be high(including ph?)....and then once it's all mixed in, then the alk. returns to your 8'ish dkh reading?

if you do nothing, does the alk. go back to 9.5-10 by itself?

 

[pdnyc69]

The ph is always the same. The kalk goes on with the ato float switch. I tried the let the alk curve back only to see it continue to go down to 7.0. This is driving me crazy. I just hope my tank doesn't crash

 

[pdnyc69]

anyone else have any ideas? last night my alk dropped from 10 to 9. so its getting a little bit better.