pH buffering question

[Cheatodude]

Hey you guys gave me good advise before, and I need to ask again!

12g nano, 4 months old about. Things are finally stabilizing and the CUC is going great and I have a mushroom that's doing really great in it. It took forever for my pH to stabilize, it was always really low, but now it's started to swing. It swings between 7.8 and 8.8 depending on before or after the light cycle.

I went to the LFS and was looking at the buffering supplies and kept seeing ones that would raise pH or lower it. Problem is, it goes above AND below the ideal mark. Anyone know of a good brand or a good plan to make it go to 8.3/4ish and you know... STAY?

Thanks.

 

[DarthPadre]

First, API Marine Buffer works very well for me. It's 8.1 - 8.2, though, not 8.3, but it does work. I actually only use it every other PWC (roughly) and the tank keeps at 8.2.

Second, I always hate to doubt people because I am often wrong, but are you SURE about those pH readings? I have never heard of a pH swing of a full point before. 7.8 and 8.8 are very very different as the scale is exponential, meaning 8.8 is ten times more basic (based on the amount of OH-) than 7.8 is. What type of test are you using?

 

[Cheatodude]

I'm using the API High Range pH test ( Aquarium Pharmaceuticals Freshwater/Saltwater High Range pH Test Kit, Test kit of 250 tests ) and it is the salt water strip. First thing in the morning, half an hour before the lights come on, it is a very light brown, where as four hours into the light cycle, it's dark purple the minute the drops hit the water. I know it's a huge swing which is why I'm looking at a good, potent buffer, especially with how small the tank is.

 

[DarthPadre]

I had a feeling it was those strips. IMO those suck. Get the wet test with the test tube and droppers. Those are much more accurate. Though you are no doubt getting different readings, this is not because the water is changing, rather the amount of water being collected on the strip isn't consistant, which is giving you a wider range of readings. My guess, your tank has been around 8.2ish the whole time. Before adding buffer, get a wet test.

 

[Cheatodude]

I am using the wet test. The "strip" is the strip with the colors to compare to the tube.

 

[DarthPadre]

Wow. I misunderstood. I don't know what to say. I don't have the API wet test (I have the Redsea), but my last suggestion would be to read the directions to ensure you're performing the procedure correctly. I used the API Nitrate test wrong the first few times because I didn't read these directions. Just a thought. Good luck.

 

[Cheatodude]

It's their most basic test. Fill it to the line, five drops, shake and wait five minutes.

 

[Chris_A]

Testing several times a day (or using a monitor) will show a fairly decent swing most of the time. But I've never heard of one that wide. Mine is from ~7.8 to ~8.3 every day. To my knowledge there's no way to make it stay constant but there are things that could help. A buffer as you said may reduce the swing. Before rushing out and buying some though, what is your Alkalinity?

 

[Cheatodude]

Ok so I've finally got the kit and ran the test. The KH reads at 8.6 and the Alk at 3.09

I had a strange concentrated outbreak of what looked like green hair algae which seemed to ... I guess die quickly as it all turned white and fell off rather quickly, leaving a lovely white slimy residue thing in the back of my tank. I think this is part of the process though as the green hair is basically all gone and no more has grown. since. My corals are all still doing good and my polyps have sprouted 4 new heads.