Why can't I raise my ph

[tp1011]

My tank is new I only have live sand in it right now the kind you get in a bag at the LFS that says live sand on it. My ph is at 7.8 Im trying to get it around 8.0 - 8.2 putting in Kent ph up
but its just not moving

Any ideas

 

[BL1]

Yep, leave it where it is. 7.8 is within normal params and is acceptable.

 

[wontonflip]

+1 brian Plus PH tends to swing depending on how long the lights have been on.

 

[Bifferwine]

In a new tank, your parameters are going to be off and swing around a bit, especially during and after the cycle. Like others have said, 7.8 is within normal range and you shouldn't worry about changing it.

 

[Smitty]

+1 everyone...stop adding products to the tank and let it naturally fix itself.

 

[tp1011]

I have no lights on the tank yet, that will happen this weekend a Kessil 350.
I would not think that would change the ph. but if you guys say 7.8 is ok

 

[BL1]

I have no lights on the tank yet, that will happen this weekend a Kessil 350.
I would not think that would change the ph. but if you guys say 7.8 is ok

Not my explanation but, this is the complicated version to why lights affect the pH in our tanks

Why Does pH Change During the Day and Night?
The diurnal (daily) change in pH in reef aquaria comes about because of the biological processes of photosynthesis and respiration. Photosynthesis is the process whereby organisms convert carbon dioxide and water to carbohydrate and oxygen. The net reaction is:

1. 5. 6CO2 + 6H2O + light � C6H12O6 (carbohydrate) + 6O2
   ​

So there is net consumption of carbon dioxide during the day. This net consumption leads to many aquaria becoming deficient in CO[SIZE=-1]2[/SIZE] during the day, and the pH rises.
Likewise, organisms also carry out the process of respiration, where this carbohydrate is converted back into energy for other processes. In the net sense, it is the opposite of photosynthesis:

1. 6. C6H12O6 (carbohydrate) + 6O2 � 6CO2 + 6H2O + energy
   ​

This process is happening all of the time in reef aquaria, and it tends to reduce the pH due to the carbon dioxide produced.
The net effect of these processes is that pH rises during the day and drops at night in most reef aquaria. This change varies from less than a tenth of a pH unit, to more than 0.5 pH units in typical aquaria. As is discussed in other parts of this article, complete aeration of the aquarium water to drive out excess carbon dioxide, or pull in excess carbon dioxide when deficient, will prevent the diurnal ph swing entirely. In practice that is often not attained, and there is a pH change between day and night.
In addition to aeration, the amount of chemical buffering in the water will impact the magnitude of the pH swing. Higher carbonate alkalinity leads to a smaller pH swing as the combination of carbonate and bicarbonate buffer against pH changes. Boric acid and borate also buffer against pH changes. Both of these buffer systems have more capacity at high pH (8.5) than at low pH (7.8), so aquarists with lower pH may see a larger pH swing for that reason alone.

 

[Bifferwine]

In layman's terms, algae and corals require light for photosynthesis. Photosynthesis takes carbon dioxide and turns it into oxygen. When it is dark, photosynthesis doesn't occur, and carbon dioxide builds up in the water. Carbon dioxide bonds with water to form carbonic acid. Carbonic acid causes the pH to drop.

This is why the pH in your tank drops at night after the lights turn off. During the day, photosynthesis is occurring and keeps the pH stable. When that photosynthesis stops, pH drops.

Having a light on your tank will help increase the pH. Having a refugium connected to your tank with a light on opposite of the main tank's light will ensure that photosynthesis is occuring 24/7 and that will keep the pH stable between day and night.

 

[reefer82]

In layman's terms, algae and corals require light for photosynthesis. Photosynthesis takes carbon dioxide and turns it into oxygen. When it is dark, photosynthesis doesn't occur, and carbon dioxide builds up in the water. Carbon dioxide bonds with water to form carbonic acid. Carbonic acid causes the pH to drop.

This is why the pH in your tank drops at night after the lights turn off. During the day, photosynthesis is occurring and keeps the pH stable. When that photosynthesis stops, pH drops.

Having a light on your tank will help increase the pH. Having a refugium connected to your tank with a light on opposite of the main tank's light will ensure that photosynthesis is occuring 24/7 and that will keep the pH stable between day and night.

Nice write up. But just curious what happens in the ocean when its night time. How does PH keep stable without any sun light?

 

[BL1]

It's always sunny somewhere in the ocean. Just like if you keep light on your sump on an opposite cycle to stabilize the pH. Also, the ocean is a completely different beast, you can't compare our tiny tanks to the massiveness of the ocean. There are chemical interactions in the ocean that we still don't completely and the water volume of the ocean also makes for small, slow changes.