PH falling in new tank.

[snodine]

The PH in my new tank is falling over the last few days.

Over the last 6 days these are the PH numbers:

8.00
7.99
7.88
7.97
7.88
7.64

I have live sand and live rock in the tank for the last 8 days.

In the last 9 days there have been 3 days of measurable Ammonia - 2 days at .50 and one day at .25. Nothing for the last 2 days.

There has been no measurable Nitrite for 5 days.

Nitrate has been at 20 for the last 7 days.

I did about a 40% water change 6 days ago after the Ammonia hit .50. It was correctly pointed out to me that it was probably too soon to be doing a water change.

I have a 55 gallon sump with a clump of Chaeto. This is lit 3AM - 8AM while the main tank is dark.

Is the PH something to be concerned about?

Thanks in advance for your assistance.

[chatyak]

Could be because of excess carbon dioxide (CO2). Do you have many windows closed? Can you open a window? Is the surface of your tank agitated well with powerheads? This could all help!

My tank is in the basement in a room and the ph stays around 8.2. I have plenty of surface agitation though.

[snodine]

Have had the window in the room open until yesterday. I have noticed a little film but only on 1/2 the tank - the end opposite the overflow. There are 3 Koralia 4's and the return but they are pointed down. There is rippling on the surface but not "white water". Maybe point a Koralia up?

[Randy Holmes-Farley]

Are you monitoring alkalinity? It is carbon dioxide and alkalinity together that determine pH in seawater. :)

[snodine]

I have not tested for alkalinity. I will pick up a test kit today.

[HappySkittles]

your tank is cycling yes?
my tank was doing the same thing while it was cycling. once it finished it was perfect...no buffers or anything except with usualy water changes and top off. i think the whole cycling process screws up the ph

[Bonneville08]

All of these are excellent points. As you have no life other than live rock at present, I would not sweat the pH yet.

[Randy Holmes-Farley]

I would measure and maintain alkalinity right from the start to encourage coralline algae as opposed to green algae. :)

[snodine]

What is a good target ph level for a new tank? What would be a good way to maintain this target level?

[snodine]

PH at 7.71 after testing just now.

[Randy Holmes-Farley]

I discuss pH issues here:

The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH
http://reefkeeping.com/issues/2007-05/rhf/index.php

[snodine]

Randy, thank you for the link. I have printed out all 4 parts and will be reading them over the next day or two. I'm pretty sure this will answer a lot of my questions.

Thanks again.

[rogergolf66]

open a window. may have already been said but prop Excese co2 in the tank. put a powerhead higher to break the surface of the water more. add a airstone if that helps then it is excese CO2

Roger

[Randy Holmes-Farley]

thank you for the link. I have printed out all 4 parts and will be reading them over the next day or two. I'm pretty sure this will answer a lot of my questions.

Hopefully it will, but if not, just pop back.

Happy reefing. :)