Basic chemistry (pH/alk) in new tank

[Annahra]

I have a 24g Nano Cube running for about a month now with following:

30 lbs live rock (lots of sponges, barnacles, macroalgae, feather dusters, small urchins, etc.)
50 lbs live sand
Ceramic rings, Chemi-Pure Blue, and Phosguard
Main pump 290gph and added 160gph powerhead
Neon dottyback
Stippled clingfish
Mandarin dragonette (dosing with pods regularly for him and I had an active culture going before adding)
~20 1/4-1/2" hermits, blue-legged and a species with white legs that came in my sand and live there
~10 various snails
Tiger tail cucumber
Spider decorator crab
Peppermint shrimp

Tank fully cycled in a couple of days, and nitrate/ammonia have been at 0 for about three weeks (other than small spike when I added second batch of live rock, up to about .25 ppm each). Specific gravity is 1.025, nitrates around 10ppm, temp 80°, calcium 400ppm. I'm doing about twice weekly 15% water changes with aged water to help keep nutrients under control until sand bed gets up and running.

I'm keeping the tank a little grungy to try and preserve as much of the life on the rock as possible. I add filter feeder food (Coral Frenzy blended with some other stuff and bottled phytoplankton) twice a day with the main pump of so I have a lot of nutrients gong into the system.

My major problem is with low pH and high alk. I was having issues with pH dropping to 7.8ish overnight (it is around 8.1 right before lights out). I added Seachem's pH buffer a couple of times per directions but it doesn't seem to make a difference and now my alk is measuring off the chart with the Salifert test. As a better strategy, I've pulled all the bio balls out of the filter and am adding a couple of LED strips to make something of 24/7 refugium in the overflow. I have some chaeto coming today. Do you this this will be a good strategy for counteracting the swings? I feel like chemical intervention wasn't doing much.

Thanks!!

 

[GoVols]

Do not use Seachem buffer. It has borate in it and it drives up alk too. Buffer only covers up the issue.
The biggest ph killer is trapped in CO2 in the home. Can you open your windows and get the co2 out and fresh air in?
Here's a help guide for you.
http://www.reefkeeping.com/issues/2004-09/rhf/

Regards, GoVols

 

[Annahra]

Thanks so much for the rapid response! Unfortunately we live in Savannah so opening a window isn't usually an option in June even at night. I could leave open the front lid of the tank at night if that might help? The hood is normally a really tight fit.

 

[GoVols]

Thanks so much for the rapid response! Unfortunately we live in Savannah so opening a window isn't usually an option in June even at night. I could leave open the front lid of the tank at night if that might help? The hood is normally a really tight fit.

You could try Randy's co2 test in that article and if it pans out. Then you could add a co2 scrubber.

 

[saltyfilmfolks]

Yup the buffer is lopsided dosing. So it brings the alk way up.

Your ph is actually not bad at all. That's a such a minor swing some folks would kill for it.
Do check it first thing in the am some time.

Currently there's very little in the tank that require really good ph control.

And thesrs actually little to nothing in there that uptakes c02. As you add coral this will change. So don't sweat it.

Be cautious of overfilling the back chambers in a cube it'll build up detritus.

 

[Annahra]

Thank you! The 7.8 is just after lights on in the AM. Have gotten into the habit of checking all values twice a day, especially since I got those large sponges with my live rock and I know they have a pretty dismal survival rate (want to see any major changes quickly).

I am planning on adding some hardy soft corals soonish (starting with tiny frags), but probably won't do SPS/LPS ever unless I upgrade lighting (2x36 watt PCs).

I'm going to pull the ceramic rings next week (wanted to give some time between pulling the bio balls and those) and then I'll just have the two little packets of chemical media back there plus a handful of chaeto under supplemental lighting. I pulled all the filter sponges the very first week--they were nasty. I want the build up in the tank where critters will eat it.

 

[saltyfilmfolks]

Yea it's a fine balance in those. You may find you want the filter floss back in at some point. Less stuff does mean less work for the skimmer.

What skimmer do you have?

 

[Annahra]

No skimmer. From what I've read (correct me please if you disagree) with such a small water volume (probably 15g with the rock and sand) I'll get better nutrient reduction from doing 15% weekly water changes, which is really no trouble.

 

[Brew12]

Your ph is actually not bad at all. That's a such a minor swing some folks would kill for it.

This +1

It is important to remember that pH is a function of Alkalinity and CO2. To change pH you need to impact one or the other. In my opinion it is much more important to coral to keep alkalinity constant than to keep pH constant. This only leaves making adjustments to CO2. Lighting chaeto at night is a good way to get some CO2 out of the tank. Running a CO2 scrubber on your skimmer or running the skimmer airline outside works, too. Personally, I wouldn't worry about it as long as your pH stays above 7.5. You may not grow coral as quickly with pH that low but you are also much less likely to kill the coral than you are by trying to raise it.

 

[Annahra]

You may not grow coral as quickly with pH that low but you are also much less likely to kill the coral than you are by trying to raise it.

This is always my first instinct (to avoid chemical solutions wherever possible). Learned that in high school keeping cichlids. Am hoping to get this system to the point where I do very little or no supplementation outside of feeding and water changes (and pod cultures occasionally to recharge for the dragonette). Thank you so much for your input.

 

[Annahra]

Got my little refugium up and running! Two LED strips, 18 bulbs and about 4 watts each, one blue, one white, and a little golfball-sized hunk of chaeto. I'm also going to try leaving the front lid open at night.