Which option is best for increasing pH?

[reefcoral]

I've just tested my pH with a borrowed pH meter and it's come out at 7.9. The 3 options available to me, and they're the only ones I know of at the moment are:

a) use pH 8.3 powder
b) use salifert pH and Kh buffer
c) use baking powder (I think?)

I'm sort of worried that the salifert stuff will also increse my Kh which is 11 at the moment.

What do you reckon is best to do? I'm just about to add some new RO water with Red Sea Coral Pro which is reading 8.3. Should I mix any additives into this before I put it into the tank or is it OK to put the additives straight in the tank?

[cav]

Before you go adding anything have you looked as to what maybe bringing the ph down? Does the tank have lots of surface movement? Is it open or closed top? Is it in a room with ventilation/air circulation? How big is the tank and what is the stocking? What are your tank params (especailly alkalinity)?

[reefcoral]

The tank is 320L, open topped, with 30kg of live rock and sand. There is an external canister filter with carbon, elimiphos and live rock rubble which returns back to the tank through a UV sterilizer. I also have a V2 800 skimer.

I have (this evening) increased the waterflow. I have a Vortech MP40W impeller at one end of the tank (up full blast at the moment), and two 30w powerheads, one at the other end and one in the middle.

In the tank are a Yellow Tang, 4 Green Chromis, a Marroon Clownfish, a Zebra Stripped Gobie, a Six lined Wrasse and a Scooter Blennie. There is one rock with clove polyps and xenia on it and that's about it. I use Red Sea Coral Pro salt and RO water.

The Calcium level = 520 and magnisium is around 1400 at the moment. The alkalinity at the moment is 11 on a Salifert test kit. I have had a little trouble of late with high Nitrate levels but Nitrite and Ammonia are 0.

What do you reckon?

[cav]

Do you have any windows open? I have to keep opening mine as when the wife and I, plus the dog, are sat in the living room with the doors shut my ph tends to drop, keeping the window open helps.

[cl0wn]

i would double check with a test kit. has the ph meter been callibrated recently?

[reefcoral]

We don't have the tank near any open windows and there's not much else of a draft near it.

The pH meter has been calibrated, and I do get a low figure for the tank water when testing with an API droplet test kit. I'm a bit fed up with testing using the droplets so I ordered a PinPoint pH monitor which doesn't work - will be on it's way back monday, so in the meantime borrowed one from a friend which seems to be spot on. When in RO water with Red Sea Coral Pro salt at 1.024 salinity the borrowed pH meter reads as 8.3, so I do trust it.

There's definately something not right in the tank as the fish seem a little stressed at the moment.

[cl0wn]

how about dripping kalk?

[reefcoral]

I don't know anything about how to drip kalkwasser, although it sounds fairly straight forward. How would this fit in with the rest of my tank parameters?

[VP Clown]

When are you testing, pH in the morning is normally 1 or 2 points lower than at night. It is important to test same time each day

Andy

[reefcoral]

I've just tested this evening and the pH was 8.03. I did a small water change yesterday which may have brought it up a little, but this still seems lower than it should be to me. I'm under the impression 8.3 is the definative target.

I'm really trying to elinminate as many issues from my tank as possible because there is something I'm doing, or a certain water parameter, which is preventing any corals from thriving. Clove polyps and a brownish xenia (non pulsing) are the only things that seem ok at the moment. I have plenty of coraline algae, although even that seems a little odd at the moment. It looks a little bleached in places.

Grateful for any advice. Dave