PhosBan & Carbon addition PH UP!?

[TexasTodd]

Hey, I just started using Carbon and PhosBan on my 1 year old sps system.

I started with the recommended amounts and flows, but timered them at only 1 hour a day and worked up slowly.

Everything in the tank is doing well with noticable improvements (lower algae and better sps growth) in the three weeks.

I have been watching my PH and Alk closely as always through this process. I saw a slight PH drop the first few days running an hour per day. Since then this has not been a problem.

I started running 24hrs/day 3 days ago now. All is good in the tank, BUT, MY ALK IS RISING! My PH has come up some too, but not much.

Nothing else has changed in my system during this period.

I though the Alk was supposed to drop if anything.

I have gone from 3.6-3.8 meQ/L range to 4.4 meQ/L.

A friend of mine here on RC warned of increasing Alk I think.

Anyone?

I can throttle back my CA reactor, but wanted to get some feedback first as to why this would happen.

Thanks much,

Todd (TT)

[Randy Holmes-Farley]

I don't think it likely that the increased alkalinity came from either the Phosban or the carbon. I'm not sure why it rose.

Some people report a drop in alkalinity when using the iron-based media, and there may be a variety of reasons for that (increased calcification by corals and coralline algae, and increased abiotic precipitation of CaCO3).

I discuss these materials more in this article:

Iron Oxide Hydroxide (GFO) Phosphate Binders
http://reefkeeping.com/issues/2004-11/rhf/index.htm

[TexasTodd]

Thank you Randy. Yes, I know that's what usually happens.

That's why I'm confused. I did clean my skimmer with 9% vinegar this week, but I always skim very wet--green tea anyway.

I checked my reactor and bubbles and flow are both dead on as they have been for a couple of months.

I think the PH can rise with lower organics, but is it at all possible for the Alk to rise from this?

I've read the article you posted many times. I knew to look out for dropping Alk from that and MANY threads. I researched this for 3 months before getting up the courage. :)

Barring any possible reasoning for the rise, is there a meQ/L point that will become dangerous for my sps's? My CA is usually really high like 500 ish.

Thanks for all the good info you give.

I can repeat again that I've seen noticable improvements and grown in the three weeks!

TT

[Randy Holmes-Farley]

I think the PH can rise with lower organics, but is it at all possible for the Alk to rise from this?

No. Alkalinity can only rise if it is added somehow (or is being continually added, and the consumption is decreased somehow).

As long as calcium is OK (not too low), I would not worry about high alk until above 5 meq/l, and even then it may be OK.

[TexasTodd]

Thanks again Randy.

Your advice is always very helpful.

Todd

[Randy Holmes-Farley]

You're welcome.

Happy reefing. :)