Vinegar dosing droping ph low

[xiholdtruex]

Have been slowly dosing vinegar to help drop high nitrates at around 40ppm , im currently at 30ml a day and monitoring ph, I find my ph regularly during lights on at 7.9 and lights off around 7.7 , when dosing vinegar I do it during lights on and my ph drops to 7.7 at lights off my ph drops to 7.6 . as a note I am running a skimmer all day with a recirculating co2 scrubber setup.

would this be considered normal drop in ph or should I be worried about it going so low? should I try using something like brightwell nitratr instead?

any recommendations are welcome

 

[vetteguy53081]

Use chemipure blue
Vinegar will strip nutrients, alk and ca

 

[arking_mark]

Use chemipure blue
Vinegar will strip nutrients, alk and ca

Curious. How does vinegar strip Ca and Alk?

 

[arking_mark]

I would expect higher pH with a recirculating CO2 Scrubber unless the tanks flow/agitation is outperforming the skimmer. Or other things are bringing down your pH.

A 7.6 pH is below what would be normally expected (assuming an 8 alk, your effictive CO2 levels would be around 2000, an unhealthy level if this is all from home air CO2).

Vinegar dosing should only temporarily reduce you pH.

What is the size of your tank? Alk levels?

 

[vetteguy53081]

Curious. How does vinegar strip Ca and Alk?

As corals absorb them typically, vinegar acid breaks them down a little dissolving inorganics and compounds as some of the measured alkalinity may be acetated.

 

[xiholdtruex]

I would expect higher pH with a recirculating CO2 Scrubber unless the tanks flow/agitation is outperforming the skimmer. Or other things are bringing down your pH.

A 7.6 pH is below what would be normally expected (assuming an 8 alk, your effictive CO2 levels would be around 2000, an unhealthy level if this is all from home air CO2).

Vinegar dosing should only temporarily reduce you pH.

What is the size of your tank? Alk levels?

90g tank alk is kept at 7.1-7.3dkh

 

[xiholdtruex]

Full parameters tested today

1.026sg
CA 420
Mg 1350
Alk 7.2
Temp 77f
Nitrate 28ppm
pH 7.52
Yesterday mid light schedule dosed
30ml vinegar
2ml aminos
2 cube size piece of lrs food
4 2x2 squares of nori

 

[Randy Holmes-Farley Verified Community Expert]

Have been slowly dosing vinegar to help drop high nitrates at around 40ppm , im currently at 30ml a day and monitoring ph, I find my ph regularly during lights on at 7.9 and lights off around 7.7 , when dosing vinegar I do it during lights on and my ph drops to 7.7 at lights off my ph drops to 7.6 . as a note I am running a skimmer all day with a recirculating co2 scrubber setup.

would this be considered normal drop in ph or should I be worried about it going so low? should I try using something like brightwell nitratr instead?

any recommendations are welcome

When I was manually dosing vinegar once a day, i saturated it with calcium hydroxide to prevent any pH dip when first added.

 

[Randy Holmes-Farley Verified Community Expert]

As corals absorb them typically, vinegar acid breaks them down a little dissolving inorganics and compounds as some of the measured alkalinity may be acetated.

I do not see how that makes sense.

Adding vinegar will temporarily reduce alk a little before it is metabolized. Once metabolized, the net effect on alk is zero.

It cannot have an effect on calcium after adding to seawater.

 

[MaxTremors]

Chemipure blue is just carbon combined with a purigen like product, it’s not an effective method of nutrient export (it’ll absorb some organic material before it breaks down, but it won’t reduce nitrates significantly). As far as your PH issues, vinegar dosing can lower your PH, but I think if your PH is consistently that low there’s something else going on or an imbalance somewhere.

 

[MaxTremors]

When I was manually dosing vinegar once a day, i saturated it with calcium hydroxide to prevent any pH dip when first added.

Can you explain your exact process in detail (saturating vinegar with calcium hydroxide)? And does this have an impact on alkalinity or calcium? I’ve been dosing vinegar for a few months and it has lowered my nitrates pretty significantly, but it has had a slight impact on PH.

 

[Randy Holmes-Farley Verified Community Expert]

Can you explain your exact process in detail (saturating vinegar with calcium hydroxide)? And does this have an impact on alkalinity or calcium? I’ve been dosing vinegar for a few months and it has lowered my nitrates pretty significantly, but it has had a slight impact on PH.

The amount of added calcium or alk is very low, but some.

Take vinegar in the bottle it came it, add several tablespoons of calcium hydroxide (added in excess and can be reused), shake gently to mix, and let it settle. Use the clear liquid.

 

[xiholdtruex]

Thanks everyone for the input this really has me baffled I'm going to try opening the windows when I get home to see if it helps. But have never had pH so low unless my probe is shot lol

 

[vetteguy53081]

The alk effect would be temporary. It was sprung that indicated at MACNA that CA also affected

 

[Randy Holmes-Farley Verified Community Expert]

The alk effect would be temporary. It was sprung that indicated at MACNA that CA also affected

I cannot see how that happens, and I think either folks misunderstood, or he is wrong.

 

[xiholdtruex]

When I was manually dosing vinegar once a day, i saturated it with calcium hydroxide to prevent any pH dip when first added.

would this cause a big change in alk ?

 

[Pistondog]

Have been slowly dosing vinegar to help drop high nitrates at around 40ppm , im currently at 30ml a day and monitoring ph, I find my ph regularly during lights on at 7.9 and lights off around 7.7 , when dosing vinegar I do it during lights on and my ph drops to 7.7 at lights off my ph drops to 7.6 . as a note I am running a skimmer all day with a recirculating co2 scrubber setup.

would this be considered normal drop in ph or should I be worried about it going so low? should I try using something like brightwell nitratr instead?

any recommendations are welcome

The additional bacteria from carbon dosing may be producing more co2. Increase surface agitation or run an airstone.

 

[Randy Holmes-Farley Verified Community Expert]

would this cause a big change in alk ?

No. Small addition.

Normal 5% acidity Vinegar saturated with calcium hydroxide will contain about 20x the potency of saturated kalkwasser, but you do not use much volume..

Thus, 50 mL added to a 100 gallon aquarium will boost alk by roughly 0.3 dKH.

 

[xiholdtruex]

@Randy Holmes-Farley would keeping my alk between 7.1-7.3 effect my ph to this level ? should I be keeping it a bit higher in the 8.0dkh range?

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley would keeping my alk between 7.1-7.3 effect my ph to this level ? should I be keeping it a bit higher in the 8.0dkh range?

The pH of seawater with an alkalinity of 7 dKH in contact with normal CO2 air levels will be pH 8.1 to 8.2, so it is not causing the low pH and raising the alk a little won't have much impact.