Alkalinity up and down daily! Please help

[ibrat82]

So my 90 gallon has 3 corals only and as of a few days ago im seeing some green coraline algae growing on my dry rock.

During this time my alk is going up and down daily. for example i started measuring my weekly alk and on friday it was down from 8.3dkh to 7.5dkh which is fine over a week, but then dosed and then tested the next day i brought it up to 8dkh then yesterday it dropped to 7.5. so i dosed again and brought it upto 8. Then checked again today and its back down to 7.5dkh.

im dosing using neptune pumps of 1.6ml over 9 hours or so. so its no prepitating by adding it too fast.

im also testing using selifert so its pretty accurate.

could it be the corraline eating all the alk? i only have 3 small frags of corals, birds nest, hairy mushroom and zoo's.

please help.. what could be causing this.

 

[username in use]

What time(s) of day are you testing? Are you also charting the ph and calcium over the same period? What are those results?

 

[Sk8r]

Stony corals can do this once they start to feed, coralline also, or clams. 90 gallons, however, is quite a draw. How is your mg level? S/b about 1350.

 

[ibrat82]

im testing in the mornings or a few hours after dosing (evening) magnesium is at 1350 calcium is at 420 and has been havent had to dose yet. My weekly water changes top off everything but alkalinity. im using aquavitro salinity which some have said to have low alk with it.

Stony corals can do this once they start to feed, coralline also, or clams. 90 gallons, however, is quite a draw. How is your mg level? S/b about 1350.

 

[2una]

Running GFO ? i find that screws with my alk dosing if i happen to add new GFO or increase the tumbling etc,whether its the gfo or the po4 its pulling out i dont know but it has a noticable effect

 

[ibrat82]

yes i am running gfo and have been since day one. can that be an issue?

 

[ibrat82]

So my 90 gallon has 3 corals only and as of a few days ago im seeing some green coraline algae growing on my dry rock.

During this time my alk is going up and down daily. for example i started measuring my weekly alk and on friday it was down from 8.3dkh to 7.5dkh which is fine over a week, but then dosed and then tested the next day i brought it up to 8dkh then yesterday it dropped to 7.5. so i dosed again and brought it upto 8. Then checked again today and its back down to 7.5dkh.

im dosing using neptune pumps of 1.6ml over 9 hours or so. so its no precipitating by adding it too fast.

im also testing using selifert so its pretty accurate.

could it be the corraline eating all the alk? i only have 3 small frags of corals, birds nest, hairy mushroom and zoo's.

please help.. what could be causing this.