What is an acceptible alk swing for acro's?

[jent]

What does most of your alk swings look like? Based off my weekly testing, I have about a 1 dkh swing every week. I do water changes every other week, and that seems to correlate to these swings. During the high points I am around 8.5, and the lows I am around 7.5.

While doing fine with every other coral I have tried, acros still seem to be a struggle for me. Usually I get STN from the base up, though recently I have had some tip burning. That said my water change, and other methods for maintaining alk and ca (which is primarily kalk in the ATO) have not changed in the last year.

I am curious how much your alk swings, and if this 1dkh swing per week might be a source of my issues in keeping acros?

 

[TUSI]

That's not to bad. Mine does the same and don't have ill effects.

 

[Chac317]

Are you at max dosing of kalk in your ATO? I use kalk and it only waivers a few ppm on the Hanna checker which correlates to .1-.2 dKH on any given day. 1 dKH a week probably isn't the end of the world but if you can increase your kalk dosing it would probably benefit the sps corals.

 

[DannyB]

I have a dosing pump on my Reef Angel which doses every hour which keeps my alk at 160ppm at all times. I have had problems with all SPS until I implemented this and now everything is really growing.

 

[jent]

Are you at max dosing of kalk in your ATO?

No, it's not. I am at 5 table spoons per 10 gallons. I do use a slow pump for pumping it into the tank, so I can go to a higher kalk concentration. I have not though since my Ca has remained very constant. It's only my alk that fluctuates at all.

 

[Chac317]

In my experience my sps has done better when concentrating on keeping alk stable and not worrying as much about what that does to calcium. Alk has more dramatic effects from what I've seen. I'd up your Kalk dosing to maintain close to constant alk levels.