PH and low salinity

[hambass]

Been lurking for a long, long time, now I need some help! Thanks in advance for a great forum and everybody’s outstanding input. I tried searching the crap out of this, so don’t even think about yelling ;)

My tank specs are:

10gal hex/flat back w/built in overflow/bio filter (filled w/LR/3lbs, no media)
Lighting; 2 36W PC’s and a 13W from AH, all new
My tank is 6 weeks old and was cycled w/about 15lbs. of uncured Fiji rock from Jeff’s
LS
Phosphate, Nitrate, Ammonia all 0
Cal 440
Kh/alk 11.8
Salt used is Tropic Marine, water used RO/DI, top off RO/DI
Using 2-part B-ionic
Kent Phosphate sponge
Reef Vital DNA
Skimming with a Prism (yes, it actually works)
Calibrated (and re-calibrated) pinpoint for PH
Using a refractometer to measure salinity

Like most people, I have been battling green hair algae. My strategy, in part, was to promote the growth of coralline. I started dripping kalk and at first didn’t think any was growing, but after scrubbing the rock to remove the green crap, I saw there was actually quite a bit there. During this time I would drip enough kalk to keep the ph as high as 8.5 during the day, which would drop down to 8.2 at night.
--HOWEVER—
To get my PH to 8.3-8.5, I need to drip about a half gallon of kalk to sustain the PH. But doing so drops my salinity to as low as 1.020. The drip is also more than my evaporation rate, so I find myself scooping out water to prevent the tank from overflowing. This, I believe, is why may salinity drops (I also tried dripping with salt instead of RO/DI, but the PH/kalk wouldn’t exceed 9 and it didn’t budge my tank ph.)

Not dripping Kalk, the tank goes to 7.9 during the day, 7.8 or 7.7 at night.

I am trying to stabilize my ph and salinity.

If I stop dripping Kalk, is 7.8 to 7.9 too low??
Will I be able to grow any coralline?
Is there some type of PH additive?

I have a cleaner shrimp, two perc clowns, all added within the past few days. I intend to get some caulerpa and a small cleanup crew. Eventually I am looking to keep some softies. This is a small tank, a refugium and top off system are out of the question.

Thanks in advance for your help! :)

C2

[MalHavoc]

First,

[welcome]

Here's a question for you, then. Any powerheads in your tank? Do you have a lot of vigorous surface movement in the tank to promote gas exchange? Do you have glass over the top of the tank?

CO2 build up is a big cause of low pH. It builds up from fish and coral respiration, and if it can't get out of the tank, it depresses the pH through the formation of carbonic acid.

If you have a spare powerhead, here's something you can try. The next time you do a water change, dump your dirty water in a bucket, and measure the pH. Drop in a powerhead, and vigorously mix it for a 24 hour period. Then, measure the pH again. If it's significantly higher (say, 0.1 to 0.2), carbon dioxide is your problem.

[hambass]

Thanks for the response, I do have 2 microjets for water movement. The tank is not covered by glass, the rear is open.

The water movement seems sufficient, nothing stagnant up top. Please also keep in mind my low PH problems existed before I added the two clowns (no corals yet), and I am using a skimmer (gas exchange?).

Nonetheless, I redirected my powerhead for better agitation!

I started thinking, maybe adding a small amount of kalk at the time I add the b-ionic, rather than dripping it?

Any other takers on this?

Thanks,

C2

[MalHavoc]

You generally don't want to add Kalk the same time you add ESV B-Ionic. The high pH mixed with all of the carbonate and calcium you're putting in the tank could cause you a lot of problems with precipitation and sand bed clumping.

[hambass]

Thanks for the responses Jason, very much appreciated.

BTW
Say hi to Ted :D :D :D

couldn't resist!!!!!


Any other takers? Bueller, Bueller??

C2

[wave_happy]

It is important to maintain a stable salinity of the proper level. Increasing evaporation by using a fan over the water surface keeps the salinity up while adding kalk. If you do not have a sump, aim the fan at the surface of the display tank. Make sure that you keep an eye on the temperature of the water. The process of evaporation will lower the water temperature.