Low dkh and lots of algae = OK pH?

[VR28man]

So, per this thread, my alkalinity is down to 5.6dkh (hanna, very confident in this measurement) now that I've come home from two weeks away. However, pH is 8.2 or so (salifert). There's also an enormous amount of hair algae in the tank, and in areas without hair algae there's a good amount of macro algae.

I would assume the pH is so "high" in relation to the alkalinity is because the tank is loaded with oxygen because of the air algae.

Is it possible that while alkalinity dropped that this increased the amount of CO2 in the water, spurring algae growth?

 

[GoVols]

So, per this thread, my alkalinity is down to 5.6dkh (hanna, very confident in this measurement) now that I've come home from two weeks away. However, pH is 8.2 or so (salifert). There's also an enormous amount of hair algae in the tank, and in areas without hair algae there's a good amount of macro algae.

I would assume the pH is so "high" in relation to the alkalinity is because the tank is loaded with oxygen because of the air algae.

Is it possible that while alkalinity dropped that this increased the amount of CO2 in the water, spurring algae growth?

Really don't know??

Have you tested your phosphates with a good and reliable kit?

 

[VR28man]

Really don't know??

Have you tested your phosphates with a good and reliable kit?

Yes. For a long time before leaving, my phosphates were below what could be detected by the Hannah low range phosphate kit (not ultra low range, mind you). Yesterday when I got back the results were probably around 0.1 .

 

[beaslbob]

the high ph could very well be due to the algae lowering co2 raising ph.

But that same algae by completing the cycle and consuming nitrates would also return carbonate.

So I suspect you may have to keep KH up by dosing baking soda. Which would also reduce calcium.

At least that's what I found out and eventually wound up just doing the improved diy two part system of dr randy holmes-farley.

my .02

 

[jsker]

Hmmmm, here is what I discovered with the Hanna tests. Make sure the plastic syringe tips for the Ca and Alk titrate are clean with no leftover residue from previous testing. In fact I tossed the tips and use a new syringe every time and then toss the syringe. I have found by doing this that I get a more consistent reading every time. I used to get really low readings with my alk and would dose up and then I was high

If you are experiencing green algae and or hair algae, this would mean that you nutrients are out of balance or even high. As Freddie @GoVols suggested test your nutrients with good test kits and your phosphates should be between .02 and .04 and nitrates of 3 to 5 ppm and they can be a little bit higher on the nitrates.

 

[GoVols]

Hmmmm, here is what I discovered with the Hanna tests. Make sure the plastic syringe tips for the Ca and Alk titrate are clean with no leftover residue from previous testing. In fact I tossed the tips and use a new syringe every time and then toss the syringe. I have found by doing this that I get a more consistent reading every time. I used to get really low readings with my alk and would dose up and then I was high

If you are experiencing green algae and or hair algae, this would mean that you nutrients are out of balance or even high. As Freddie @GoVols suggested test your nutrients with good test kits and your phosphates should be between .02 and .04 and nitrates of 3 to 5 ppm and they can be a little bit higher on the nitrates.

I've had old live rock leach out phos. like new dry rock.

Could not detect phos. with a kit, because it was trapped inside the GHA.

(lol)
Took awhile to figure that one out...

 

[jsker]

I've had old live rock leach out phos. like new dry rock.

Could not detect phos. with a kit, because it was trapped inside the GHA.

(lol)
Took awhile to figure that one out...

That when I got me one of them there Hanna Ultra low phosphate checkers Then I dosed the system with a couple of dose of Lanthanum Chloride

 

[GoVols]

That when I got me one of them there Hanna Ultra low phosphate checkers Then I dosed the system with a couple of dose of Lanthanum Chloride

Well,
You wrote the book... ;Writing when it comes to testing.

Those are some great articles... ;Woot ;Woot

 

[Randy Holmes-Farley Verified Community Expert]

So, per this thread, my alkalinity is down to 5.6dkh (hanna, very confident in this measurement) now that I've come home from two weeks away. However, pH is 8.2 or so (salifert). There's also an enormous amount of hair algae in the tank, and in areas without hair algae there's a good amount of macro algae.

I would assume the pH is so "high" in relation to the alkalinity is because the tank is loaded with oxygen because of the air algae.

Is it possible that while alkalinity dropped that this increased the amount of CO2 in the water, spurring algae growth?

Not loaded with O2 (it has no effect on pH), but depleted in CO2.

High pH means low Co2,

 

[GoVols]

Not loaded with O2 (it has no effect on pH), but depleted in CO2.

High pH means low Co2,

Randy,
Is there any link with / alk / ph / in leading to GHA?

Thanks, Freddie

 

[Randy Holmes-Farley Verified Community Expert]

Randy,
Is there any link with / alk / ph / in leading to GHA?

Thanks, Freddie

Some types of algae may grow better at lower pH due to more CO2, but some get carbon from bicarbonate, so pH is not important but alk might be.

Lots of algae will lead to higher pH due to consumption of Co2 by photosynthesis.

 

[VR28man]

Not loaded with O2 (it has no effect on pH), but depleted in CO2.

High pH means low Co2,

Sheesh. Picky picky. You sound like an academic............


. (seriously, you are right of course. Thanks Randy, and all the posters on this thread!)