Alk stalls? Is this normal?

[BeMoto]

I test my alkilinity every night at 9 Pm. I test with Red Sea Alkilinity Pro. My water stays steady @ temps between 79-80, cal is 500 and mag is 1500 and salinity stays 1.026 +/- .oo1.

I've noticed my alk will be stay at 9.0 dkh for 3 days and then drop to 8.4 dkh on the 4th night. I dose red sea foundation B 12ML and the next day it is back to 9 DKH.

Is it normal for Alkilinity to stall? I only have a hand full of sps and very little coralline algea.

My sps is growing so I'm not overly concerned but found it odd my DKH stalls. I was ready to buy a dosing pump but reconsider after seeing this trend.

I wonder if the accuracy is effecting my readings. I have also tested Several times a night and end up with the same reading.

The accuracy of the test is +/- 1 dkh / .36L
My tank valume is roughly 55 gallons, 200 liters. Witch is what I have been dosing too.

Any input is appreciated!

 

[lapin]

Could you be adding water or something on the 4th day to cause the drop?

 

[BeMoto]

I have an ato that tops off rodi water. When I do water changes I buffer the water to 9 dkh closest as possible.

 

[Garf]

I would just add 3mls a day. Maybe just a test repeatability issue. Keep testing

 

[Randy Holmes-Farley Verified Community Expert]

There's no reason to expect what you report, and I think test error is the most likely reason unless your water changes are stirring things up a lot and altering the tank in a way that takes a few days to settle down again.

It is true that the lower the alkalinity, the lower the demand for alkalinity will be, but that does not explain what you see.

 

[BeMoto]

So I shouldn't be worried on what I'm seeing. Here is my notes from the beginning of the year.

What is considered DKH swing where I should be worried about? Sounds like I was chasing the number 9 around to close, and a drop of .6 isn't something to be worried about over a couple of days.

 

[syilk1]

Boy I wouldnt worry about a little drop like that. My tank swings wildly LOL and SPS growing like weeds.. Not advocated obviously but I dose about 400mls of 2 part a day. .6 would be a win in my book LOL

 

[Randy Holmes-Farley Verified Community Expert]

Too much scrawl to read. lol

A typed table would be nice.

 

[BeMoto]

Too much scrawl to read. lol

A typed table would be nice.

Not a table but easier to read. This is for the last 34 day

Dkh/Dosed.
9
8.4
9
No test
9
8.4 dosed 10ml
8.4 dosed 12ml
9
8.4 dosed 12ml
8.7 dosed 5ml
8.4 dosed 12ml
9
9
8.4 dosed 6ml
8.4 dosed 12ml
8.4 dosed 12ml
9
9
9
9
8.7
8.1 dosed 15ml
9
9
9
9
9
8.4
8.4 dosed 15ml
8.4 dosed 15ml
9
9
9
8.7 dosed 6ml

 

[Randy Holmes-Farley Verified Community Expert]

I expect there is a testing limitation in seeing the actual drop since it is unlikely to stay steady for a few days then drop 0.6 dKH in one day.

I'd suggesting dosing a small amount every day, such as 4 mL, and see how that goes.