Why is my alkalinity high and pH low

[TWYOUNG]

I have a 1yo 130g tank with only a few small frags added 1mo ago. Add 20mls AFR daily and until 2mo ago also added 2L kalk to maintain an alk of 10. At that time alk jumped to 11.5 and kalk dosing was stopped. Alk has remained 10.0-10.5 without resuming dosing. pH was 8.1-8.4 throughout the daily cycle but 1mo ago began dropping to 7.85 at night and peaking at 8.05. Adding a CO2 scrubber has improved things to 8.0-8.2.
Why is my alk remaining high, and is the absence of kalk dosing causing my lower pH?
Also why isn't my alk level dropping, and at 10 why isn't it doing a better job of buffering my pH? Sorry if this is a dumb question but I find the chemistry of this difficult to comprehend.

 

[Suohhen]

Have you tested for calcium?

 

[Propane]

What’s your mag. at?

 

[Salty_Northerner]

Yup I'm with @Propane on this one. Check the mag. I wouldn't even bother with checking calcium as I'm learning that calcium and ALK work together in a sense. Hmm trying to recall what Randy from BRS said. There's 2x alk vs cal and 3x mag. So if cal was 400 the dkh would be around 8 and mag around 1200?

So a dkh of 10 would be 500 cal and mag around 1500?

@Randy Holmes-Farley does that sound kinda sorta how it would be? Please correct me if I'm out of the park on this one :/

 

[jda]

Low pH is almost always from high airborne co2 in your home, or where ever the tank is. You can do many things to help, but nothing works as well as getting fresh air into your home. If a co2 scrubber worked, then new air certainly would too.

I might suggest a co2 meter - they are $40-60 on amazon. If you co2 is high, there can be benefit for the humans and pets too.

 

[Salty_Northerner]

I have a 1yo 130g tank with only a few small frags added 1mo ago. Add 20mls AFR daily and until 2mo ago also added 2L kalk to maintain an alk of 10. At that time alk jumped to 11.5 and kalk dosing was stopped. Alk has remained 10.0-10.5 without resuming dosing. pH was 8.1-8.4 throughout the daily cycle but 1mo ago began dropping to 7.85 at night and peaking at 8.05. Adding a CO2 scrubber has improved things to 8.0-8.2.
Why is my alk remaining high, and is the absence of kalk dosing causing my lower pH?
Also why isn't my alk level dropping, and at 10 why isn't it doing a better job of buffering my pH? Sorry if this is a dumb question but I find the chemistry of this difficult to comprehend.

Hey only I'm allowed to ask a dumb question so your out of the woods on that question

Also AFR doesn't raise the pH like Mr Randy said in other posts. As for the lower pH I'm leaning with @jda and his comment on CO2 in the room.

 

[TWYOUNG]

Have you tested for calcium?

398 Friday

 

[TWYOUNG]

What’s your mag. at?

1400 as of Friday

 

[TWYOUNG]

Low pH is almost always from high airborne co2 in your home, or where ever the tank is. You can do many things to help, but nothing works as well as getting fresh air into your home. If a co2 scrubber worked, then new air certainly would too.

I might suggest a co2 meter - they are $40-60 on amazon. If you co2 is high, there can be benefit for the humans and pets too.

As I stated the CO2 scrubber helped but it seems odd this issue only arose in the past month. Plus it's a large two level home with only three adults and a dog who are usually on the upper level while the tank is on the lower.

 

[Suohhen]

As I stated the CO2 scrubber helped but it seems odd this issue only arose in the past month. Plus it's a large two level home with only three adults and a dog who are usually on the upper level while the tank is on the lower.

Seasonal variations on weather often cause people to keep windows and doors closed when it is too hot or cold outside. The fact that the CO2 scrubber worked means you have elevated levels of CO2 in your home but it does not necessarily mean that is the only thing affecting your ph. Regardless the fact that the scrubber brought you back into a good range is all you need to do for now as making small changes is ideal.
The fact that your alk/calc depend has dropped off could be due to the change in levels and likely more significantly by the drop in ph.

 

[TWYOUNG]

Seasonal variations on weather often cause people to keep windows and doors closed when it is too hot or cold outside. The fact that the CO2 scrubber worked means you have elevated levels of CO2 in your home but it does not necessarily mean that is the only thing affecting your ph. Regardless the fact that the scrubber brought you back into a good range is all you need to do for now as making small changes is ideal.
The fact that your alk/calc depend has dropped off could be due to the change in levels and likely more significantly by the drop in ph.

Thanks. It seems we keep our house sealed up all year dt heat, cold, allergies, noise etc.

 

[hunterallen40]

I think the answer is actually the switch to AFR from kalk. Kalk provides a decent boost in pH (especially when dosing 2L / day), but AFR actually consumes O2 while creating alkalinity (though this should not be a noticeable amount, to my understanding).

I think you are just missing the heavy lifting kalk was doing .

 

[Suohhen]

I think the answer is actually the switch to AFR from kalk. Kalk provides a decent boost in pH (especially when dosing 2L / day), but AFR actually consumes O2 while creating alkalinity (though this should not be a noticeable amount, to my understanding).

I think you are just missing the heavy lifting kalk was doing .

Kalk reacts with CO2, I haven't heard anything about consuming O2. How it compares with afr idk

 

[Miami Reef]

Using ANY method of raising pH (except fresh air to the room) is typically fighting against aeration at the tank top with high CO2 air. High aeration and high CO2 often wins out.

 

[hunterallen40]

Kalk reacts with CO2, I haven't heard anything about consuming O2. How it compares with afr idk

To be clear, I was not implying Kalkwasser consumes O2 at all.

AFR indirectly does from the bacteria that create the alkalinity, as I understand it (take that with a grain of salt, as I do not use it).

My point was this: the big pH boost from kalkwasser is gone, and AFR does not provide the same type of boost in pH when it increases alkalinity.

 

[gbroadbridge]

I have a 1yo 130g tank with only a few small frags added 1mo ago. Add 20mls AFR daily and until 2mo ago also added 2L kalk to maintain an alk of 10. At that time alk jumped to 11.5 and kalk dosing was stopped. Alk has remained 10.0-10.5 without resuming dosing. pH was 8.1-8.4 throughout the daily cycle but 1mo ago began dropping to 7.85 at night and peaking at 8.05. Adding a CO2 scrubber has improved things to 8.0-8.2.
Why is my alk remaining high, and is the absence of kalk dosing causing my lower pH?
Also why isn't my alk level dropping, and at 10 why isn't it doing a better job of buffering my pH? Sorry if this is a dumb question but I find the chemistry of this difficult to comprehend.

Do an aeration test.

Take a sample of tank water outside and aerate with an airstone.
Measure the pH before and after aeration

If the pH has risen after aeration you have high CO2 in the house which you need to fix, or you can run the skimmer airline outside.

Re the Alk, I assume Alk demand in your tank with only a couple of frags is not high enough to require supplementing.

 

[Suohhen]

To be clear, I was not implying Kalkwasser consumes O2 at all.

AFR indirectly does from the bacteria that create the alkalinity, as I understand it (take that with a grain of salt, as I do not use it).

My point was this: the big pH boost from kalkwasser is gone, and AFR does not provide the same type of boost in pH when it increases alkalinity.

I'm sorry I read your post as suggesting to switch to afr from kalk rather than dropping kalk was the cause. The boost from kalk is only temporary but yes switching from afr to kalk could help increase ph I would just wait a bit as the scrubber change is already enough to get into a good range and making changes too fast can be bad.
Also yes the way to make sure co2 in the home is the cause of your ph issues is with the aeration test mentioned above. My bad for suggesting the co2 scrubber proves that. I have been away from the hobby for a while so my memory gets fuzzy on some of these things.

 

[TWYOUNG]

I think the answer is actually the switch to AFR from kalk. Kalk provides a decent boost in pH (especially when dosing 2L / day), but AFR actually consumes O2 while creating alkalinity (though this should not be a noticeable amount, to my understanding).

I think you are just missing the heavy lifting kalk was doing .

I didn't "switch". I was using both. AFR was supplementing trace elements but wasn't keeping alk where I wanted, (10), so I started adding kalk. System was very stabile for many months on around 2L kalk/day, ( It was on a DOS pump and administered overnight). Suddenly alk went up to 11.5 two months ago so I began what I thought would be a brief pause. Alk fairly rapidly decreased to 10 but has remained there since. I sent ATI labs Friday so perhaps I'll find my Hanna alk results are off but I doubt that is the issue.

 

[Randy Holmes-Farley Verified Community Expert]

I have a 1yo 130g tank with only a few small frags added 1mo ago. Add 20mls AFR daily and until 2mo ago also added 2L kalk to maintain an alk of 10. At that time alk jumped to 11.5 and kalk dosing was stopped. Alk has remained 10.0-10.5 without resuming dosing. pH was 8.1-8.4 throughout the daily cycle but 1mo ago began dropping to 7.85 at night and peaking at 8.05. Adding a CO2 scrubber has improved things to 8.0-8.2.
Why is my alk remaining high, and is the absence of kalk dosing causing my lower pH?
Also why isn't my alk level dropping, and at 10 why isn't it doing a better job of buffering my pH? Sorry if this is a dumb question but I find the chemistry of this difficult to comprehend.

The drop in pH in a closed up home that stopped using kalkwasser and kept using a product that has a tiny pH drop seems as expected: the pH dropped.

I don’t think we need to look further for other explanations, but there are many ways to help the pH.

 

[TWYOUNG]

The drop in pH in a closed up home that stopped using kalkwasser and kept using a product that has a tiny pH drop seems as expected: the pH dropped.

I don’t think we need to look further for other explanations, but there are many ways to help the pH.

Thanks Randy. I'll post when I get my ICP labs back but my thinking was I needed AFR for everything besides alk and I was needing the kalk to keep my alk where I wanted it. Do you care to speculate as to why I'd go from needing 2L kalk/week to NONE for the past 2mo.?