High Alk Tanks

[FragIt]

Can anyone tell me the pros and cons of running my alk above 10.5? Any and all responses are helpful and appreciated.

[Juiceman]

My coraline has been crazy, but other than that, I've had great growth.

[JasonJones]

Pros: your alk has farther to fall and still be acceptable. Growth may be increased, but this is usually from higher Ca than alk.

Cons: can burn tips of acros, especially if dosing a carbon source. Greater chance of precipitating Ca and alk if you don't keep Mg levels high

[subsea]

What are you using to maintain alkalinity?

In the past, when using low pH (less than 6) well water for a makeup source, I used a calcium reactor and used alkalinity to control with. I have seen people attempt to control with both high calcium and high alkalinity. Bad recepie for a disaster, snow storm of precipitation of calcium falling out of solution. This is not colateral damage, but if you have seen it happen in your prized reef tank, it seems as if it is colateral damage. I have seen this once, not a good day in Bedrock. More normal response is for high alkalinity levels to bind up grains of arrogonite in the sandbed. I have had to break up this cement/gluing of substrate ith a knife.

[FragIt]

a friend and I are discussing the merits of alk being above the minimum levels. We have both recently seen the effects of a drop in alk (below 6) for more than a few hours. I prefer to run mine a littler higher for the buffer zone rather than target, He has chosen in the past to maintain his levels with water change only and recently had a dip that caused some problems. I dose with Seachem 8.4......Never had any issues with precipitate or burned edges, but I try to keep my alk at 10 or better. My calcium rides high as well with 440 being last test.....Ive heard all about absorption rates and I do know in Florida there are tanks running 17 alk and over 500 calcium......Still researching those guys......I use a minimum of substrate...cc.....My corals look great and have flourished for over a year and a half......

I am mainly curious....am I wasting time keeping my levels high?

I was also under the impression that lower Calc causes encrusting growth to become accelerated albeit more fragile?

If any effects be they neg or pos would cause it to be unhealthy to any aspect of tank balance?

Are the normal fluctuations in Ph and Alk throughout the day enough to cause a tank to dip and spike enough to cause undue stress even if the levels fall above the minimum?

[ManImTheMan]

once i got my alk up and kept it there for a while. i had to dose cal/alk less often. it helped stabilze my levels. was dosing everyday! but now every 4 or 5 days.

[subsea]

Fragit,

High levells of alkalinity and calcium are a wasteful expense in my opinion.

[Timfish]

Generally I like to see mine around 8 - 10 dKH (reefs are 6-7) but would not intentionally try to push it higher. I've seen one of my tanks go to 17 without any apparent problems with the corals (used several big water changes over a couple of weeks to bring it down). Corals can adapt to a wide range of conditions but what I would be concerned about is acclimating corals that were maintained in 6-7 to a tank with 10, 12 or higher, at what point is the change adding enough stress that it is reducing the corals chances of acclimating properly. And the reverse is also a concern as well. Another concern is what happens over a period of a year or more, might it accelerate growth initially but weaken the coral long term? And in maintaining a high alkalinity is it possible a runaway condition might be created where the alkalinity increases in a very short time (I still don't know why the alkalinity climbed in my tank, it has a calcium reactor which maintained it before and after and was constantly monitored [weekly 5% water changes with RO/DI])?