Problems with PH

[jkuchcik]

I have always had problems with PH in my MT. I average around 7.8. On occasion I get into the 8.0 range, but only when I open the windows in my home.

Recently I relocated my sump down to my basement, not only for ease of maintenance, but it also allowed me to run a 1 1/2" PVC duct directly outside of my house approx. 15' away from my protein skimmer. My hope was that I could connect my protein skimmer venturi intake tube directly to the duct to get fresh air introduced into the water.

Upon doing this, I did see slight improvements, although I was still not exceeding 8.0. So then I thought maybe the fresh outside are was not getting into the duct enough to make it 15' to the skimmer. So I built a small duct fan in the middle of the 15' run thinking it would suck the air from outside and induce it into the skimmer. I am still not getting the results I expected.

I have attached pictures of my configuration so you can see my setup.

I am reaching out to this group to see if anyone has had similar experiences and could recommend a solution, other than running a CO2 scrubber, that may help me get better PH results.

BTW, PH Probe is new and was calibrated a couple weeks ago.

 

[NanJ]

Following.

 

[chipmunkofdoom2]

Can you clarify how your outside air is getting drawn into the skimmer? It appears the skimmer is drawing air from two sources, one being the Poseidon box and one being the outside air source.

Also, typical aeration methods will actually lower your pH if concentrated CO2 is the problem. Water movement like powerheads at the surface and water going down the overflow increases gas exchange, but if the air in your house has really high CO2, that CO2 gets worked into the aquarium water. If you have a lot of surface agitation or a vigorous overflow, this could be working CO2 back into your water and reducing the impact of the outside air.

What is your alkalinity and how do you replenish it?

 

[jkuchcik]

Can you clarify how your outside air is getting drawn into the skimmer? It appears the skimmer is drawing air from two sources, one being the Poseidon box and one being the outside air source.

Also, typical aeration methods will actually lower your pH if concentrated CO2 is the problem. Water movement like powerheads at the surface and water going down the overflow increases gas exchange, but if the air in your house has really high CO2, that CO2 gets worked into the aquarium water. If you have a lot of surface agitation or a vigorous overflow, this could be working CO2 back into your water and reducing the impact of the outside air.

What is your alkalinity and how do you replenish it?

Thanks for the reply.

In response to your questions:
Q1- How your outside air is getting drawn into the skimmer?
R1 - Their are 2 venturi tubes that go into my Skimmer pump. (1) 3/16" dia and (1) 3/8" dia. As of now, the 3/16" tube is connected to the Poseidon Ozone which is pulling ambient air within the room. The 3/8" tube is capturing outside air through the 1 1/2" PVC which runs outside the house. Furthermore, the 1 1/2" PVC has a small fan that I built which is forcing the outside air into the skimmer.

Q2 - Concentrated CO2 problem.
R2 - I agree with this paragraph as my guess is that a majority of the CO2 in my home exists on the first floor where my display tank resides. The water movement produced by the Gyer in the display tank is saturating the water with CO2 and then introducing it down the overflow into the sump. That may explain why when I open the windows the PH does go up significantly. It is almost like they are fighting each other. Meaning: When the windows on the 1st floor are closed, the display tank is getting saturated with CO2, going down the overflow (via gas exchange) and the skimmer (located in the basement) is attempting to keep up with the CO2 saturated display water and unable to do so effectively.

Q3: What is your alkalinity.
R3 - As of this afternoon, my ALK = 6.61 on the trident. I have been attempting to slowly raise this day to day to get it between 7 and 9 DKH. At this time, the Trident is controlling the DOS amounts.

 

[chipmunkofdoom2]

I see, I didn't know that was an ozone generator. That could be part of the issue. Instead of drawing only outside air, you're also still drawing air from your home as well. Can you feed the ozone generator using the outdoor air supply? I don't know much about ozone so I don't know if that's an issue for the generator. But that may help.

Regarding the gas exchange, you may not be able to do anything about that. You could try to reduce the surface agitation in the tank, but I'm hesitant to recommend that because gas exchange also supplies oxygen to the tank.

Alkalinity is probably where you have the most room for improvement. Getting the alkalinity up to between 7 and 9 dKh will help all on its own. A reef tank's pH is generally higher given higher carbonate alkalinity and static CO2 levels.

You also could use Randy/Jim's new two-part formula, which uses sodium hydroxide for the alkalinity supplement. The formula with sodium hydroxide has a very potent pH boost, one of the best you can get from a liquid additive.