Can't keep my Ca up - used Kalk, turbo calc, and 2 part

[karimwassef]

Is dosing 2 part equivalent to kalkwasser?

[karimwassef]

Since my dKH is high relative to where my Ca is, should I boost Ca a little to get up to 13dKH at 460ppm Ca?

[Randy Holmes-Farley]

It is mostly equivalent to limewater, but a good two part will also maintain magnesium and possibly other ions (such as potassium) while limewater adds none.

13 dKH seems excessively high to me. I recommend targeting 7-`11 dKH, and I'd let it decline.

[reefwars]

as a starting out goal id shoot for around 8.5 dkh , this is the mid point and then see what you like for a permanent goal.

i keep my zoanthid systems at 8 dkh but my mix reefs tend to be a bit higher , it just worked out that way and seems to keep everbody happy

[karimwassef]

So how do I walk down the Alkalinity without bombing my pH?

I feel stuck.

[karimwassef]

I'm thinking that I add just calcium and let the system consume the Alk.

I was targeting 12dKH to accelerate my coralline growth and reduce my hair algae (tank is still cycling, not steady state nutrients).

[Randy Holmes-Farley]

You may not need to dose anything while the alkalinity declines as calcium will only drop maybe 20 ppm to get alk to 10 dKH. But if you want to keep it at 440 ppm, then dosing some seems appropriate.

[bertoni]

The pH difference between 11 dKH and 13 dKH should be small. This article shows one graph:

http://reefkeeping.com/issues/2004-09/rhf/index.htm

I think you're worrying far too much about the pH.

[karimwassef]

It's down to 8.0 today... With an Alk of 13, how can my pH drop so far in 24hrs?

[karimwassef]

[Randy Holmes-Farley]

pH is related to the CO2 in the water, and that, in turn, is related to the CO2 level in the air that the tank is exposed to. Many homes have elevated CO2 and hence low pH.

This has more:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

[karimwassef]

I get that but my air intake is from the outside (see above detail).
My house air never touches the tank.

[Lavoisier]

I hesitate to even suggest such a thought but could there be any local air quality issues in Dallas that could lead to a high CO2 intake? I'm baffled by the results you are experiencing given the steps you've taken to mitigate the lower ph and calcium readings.

[Randy Holmes-Farley]

I wouldn't worry about pH unless it drops below pH 7.8.

That said, the tank top is not open to the air? Perhaps the tank itself needs more aeration. I explain how to diagnose that here:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

[karimwassef]

Great article. I came across it a few weeks ago when I started experiencing low Alk.

The tank top is open but all of the open vessels are in
My garage. There is no respiration in the garage to create excess CO2 except for the tank itself.

At 13dKH (4.6 meq) and a pH of 8.0, I am very high on dissolved CO2.

My aeration is very high with a 12 ft skimmer drawing external air only:



When I moved the intake air from inside to outside, I saw a 0.1 pH increase.

[karimwassef]

Also, I turn my skimmer off at night. That's when the pH usually plummets from 8.2 (late evening) to 8.0 (early morning).

[bertoni]

Hmm, that would suggest that the tank might need more aeration at night, although the difference could be due to photosynthesis stopping.

[karimwassef]

My skimmer is overpowering so I can't use it 24hrs a day. It would deplete all essentials...

I can't leave the garage door open for obvious reasons (safe neighborhood but still)

So ... That leaves heavy venting and external air ducting?

[bertoni]

The problem might be gas exchange between the ambient air and the water column.

[karimwassef]

?
So the main tank gas exchange is overwhelming the skimmer's?

[bertoni]

I am not sure, but that's possible. Other people have reported results like that.

[Randy Holmes-Farley]

I agree that lack of aeration at night appears to allow CO2 to build up.

[karimwassef]

Ok. So I opened up both garage doors for 8 hours (8 am to 4pm) to see the effect of fresh air - it doesn't look like it did anything to change the course it was already on. Now bottoming at 7.95!



Additionally, I only have two chromis in my tank and one of them died today. It was breathing heavy and unable to fight the water flow. It was hovering on the sand bottom. When it died, it's face was a dark navy blue (in contrast with its body).

The other chromis looks unaffected. The crabs and snails look fine.

[karimwassef]

I've dropped all additives. No kalkwasser, no two part, no feeding (I was only feeding brine shrimp twice a week anyway).

[karimwassef]