Alk question

[peteyboyny]

Ran some tests yesterday and came up with some strange results. This is just to get some feedback and a possible solution or at least a cause for the situation. My KH test might be bad so I'm gonna try that first. Parameters were as follows:
Temp - 78.8
pH - 8.0
SG - 1.025
Ca - 520
Mag - 1300
KH - 4
I only have LPS and softies in my tank. Don't really understand why my KH would be so low. All are healthy and thriving. Hoping the test solution is bad. Gonna pick up anew one today. Just wanted to see if anyone might know some more about this. Thanks.

 

[JonnyJ]

What are you testing with?

Your calcium is very high

 

[peteyboyny]

What are you testing with?

Your calcium is very high

API test kits except the mag test, its a Red Sea mag test.

 

[JonnyJ]

Never had any luck with API kits. They are good for a general ballpark when I used them.

How often are you doing water changes and how many gallons etc?

Post a photo of tank and more info

Alk can certainly get out of wack from consumption, bad salt, not allowing salt to mix well etc... Hard to tell what exactly is going on.

You can also make a fresh gallon of salt, let it mix well and test water change water to compare etc..

 

[peteyboyny]

Just switched from Kent salt(sucks) to reef crystals. I do small WC every 2wks. Its a 140g. Will post pics in a bit.

 

[peteyboyny]

I'm at work so, posting as I can. My water changes are btwn 10-15g every 2 wks.

 

[peteyboyny]

Like I said, nothing is showing any signs of stress. All corals are thriving. I can only post pics from my phone through photobucket, and some pics aren't so good. My tank has been up and running for almost 2yrs. It has also been under construction for the last 8mos as far as rockscaping (DIY rock that I have been adding over the last month).

 

[peteyboyny]

Pics
http://m1268.photobucket.com/albumview/albums/peteyboyny/21fbb467-4b27-43d4-9033-4321c87cb81a.jpg.html?newest=1&pbauth=1_uLEBonVPfaLdh1h3YMYz2bRPjmFvTcYqwcrshksXj3ZOBYFDlNs1mRFYxXfs%2B9%2FtB3p5stQZPfT8HcrIjHRCH%2Fv50SZqbQhr3tsutaq%2F1TgWt%2FYe8pYM5a%2FJQVFl8JNVNb6G05t%2F9Uc2bXPFl%2F8e6WfCTGlDLD7D9R2Vd4KUrlM%3D&pbauth=1_uLEBonVPfaLdh1h3YMYz2bRPjmFvTcYqwcrshksXj3ZOBYFDlNs1mRFYxXfs%2B9%2FtB3p5stQZPfT8HcrIjHRCH%2Fv50SZqbQhr3tsutaq%2F1TgWt%2FYe8pYM5a%2FJQVFl8JNVNb6G05t%2F9Uc2bXPFl%2F8e6WfCTGlDLD7D9R2Vd4KUrlM%3D

 

[mbg75]

Your high cal is pushing the alk low. Either water change with a low cal salt or dose up the alk slowly.

Also. API alk test does go bad. Make sure it's a fresh kit

 

[peteyboyny]

I've tried dosing sodium bicarb to raise the all, never stays up. Always drops in a day or so. When I was using the Kent salt, I got a KH reading of 6 on freshly mixed batch. That's why I switch to RC.

 

[peteyboyny]

Also. API alk test does go bad. Make sure it's a fresh kit

That was my first thought. The test solution is 1 1/2 yrs old.

 

[mbg75]

Get a new kit.

 

[peteyboyny]

Picked up another API KH test. Still coming up with 4.

 

[mbg75]

Start dosing alkalinity slowly to raise it up. Your calcium is high and that is part of the issue.
Again. Don't raise the alk too fast

 

[Boomer]

Don't really understand why my KH would be so low.

Jonny hit the nail on the head.


When your run very high calcium levels, at pH's around 8 or higher, the Alk is pulled out of the water as it combine with Calcium.

Ca++ + CO3-- ----> CaCO3 ( solid, as Calcite)

You will not see much of a shift in the Ca++, as for every 20 ppm Ca++ that leaves it takes 2.8 dKH with it. Next issue is if you add to to quickly or all at once. The local pH, Alk and Ca++ is so high, in that "local area" you added it, forms CaCO3 very readily, usually seen by a white cloud in the water of that "local area'".

Solution, do not add any more Ca++ and when bumping up the Alk just add a little at a time it in a area of high current, wait and add more 1 hr later.

 

[peteyboyny]

I have been dosing 1 oz/day of a sodium bicarbonite solution to raise the alk. Is there a better way? What to do about my rock work as well? Is adding new rock adding Ca++?

 

[Boomer]

Add the 1 oz / day but not all at once and spread it over time, i.e., like 1/4 of 1 oz, wait a couple of hrs do another 1/4 of the 1 oz.

What kind of rock work is it ? Is it home made ?

 

[peteyboyny]

What kind of rock work is it ? Is it home made ?

Yes, its homemade. 1:4:2. #1 Portland, crushed arragonite, rock salt.

 

[Boomer]

Pete, how new is it ?

 

[peteyboyny]

Brand new. Been soaking it out for the last 8 mos. R/O baths, vinegar baths, muriatic acid baths, just coming out of the colonization tank into my DT.