Low pH, interested in trying Kalk, have a couple questions

[Calm Blue Ocean]

A little background into my pH. Without opening windows and running exhaust fans my pH tends to be in the 7.7 to 7.8 range. With the window open and the bathroom exhaust fan running I can almost make it to 8.1 some days with a swing down to 7.8 at night. Unfortunately open windows aren't super practical all the time (as my latest electric bill shows). Skimmer is too small to make good use of a CO2 scrubber or to extend the air line too far (considering upgrading but not today).

Thinking of trying kalk.

First concern is that my alk is already on the higher side at 10.2 to 10.4 (IO salt) and moves very little between water changes. To get a pH increase will I still be able to keep my alk in check or is this just not the way things work?

Second, if kalk is a possible solution to my low pH, it will probably be dosed with my ATO (at least to start) since that's equipment I already have. I suspect I will have to add cleaning the reservoir to my list of regular chores. Should it be cleaned on every refill? Also I've had a handful of ATO malfunctions over the past year (and I've heard kalk can mess with optical sensors), how dangerous is a kalk overdose? The high water safety kicks in after about a quart or so overfill.

System is just over a year old, fairly simple AIO, a couple dozen frags with a mix of softies, LPS, and easier SPS.

 

[arking_mark]

I have found that Kalkwasser provides a nice stable pH boost when slowly dripped into your system. However, this requires either a kalk reactor or a simple gravity drip feed.

If you go the ATO option, your pH and Alk dosing will be subject to you evaporation rate and may be less stable and harder to hit your alk consumption rate.

If you do go the ATO route, I suggest you measure your evaporation rate and your Alk consumption for your tank. Then spike your ATO with the amount of Kalk that will keep your tank Alk stable.

 

[Calm Blue Ocean]

I have found that Kalkwasser provides a nice stable pH boost when slowly dripped into your system. However, this requires either a kalk reactor or a simple gravity drip feed.

If you go the ATO option, your pH and Alk dosing will be subject to you evaporation rate and may be less stable and harder to hit your alk consumption rate.

If you do go the ATO route, I suggest you measure your evaporation rate and your Alk consumption for your tank. Then spike your ATO with the amount of Kalk that will keep your tank Alk stable.

Thanks for the reply. Looks like setting up a drip feed is pretty low tech and inexpensive so probably worth it even as proof of concept. I'd really like to stop air conditioning the outdoors lol.

 

[reefingaz]

I set up my dosing pump to add kalk and my ph is stays solid 8.2-8.3 over 24hrs. I have dialed down the 2 part and between those my tank has never been more stable. I recommend dosing kalk and not doing in on ÁTO, that works For many, but it’s a possible disaster waiting to happen of ato dumps it all in

 

[vtecintegra]

If your alk is already 10.2 and not dropping, I don't see how kalk can be added without going too high. 10 is already higher than a lot of people like. I don't think this is going to work.

 

[Calm Blue Ocean]

If your alk is already 10.2 and not dropping, I don't see how kalk can be added without going too high. 10 is already higher than a lot of people like. I don't think this is going to work.

That could be another consideration...switch to a salt with lower alk to give me some wiggle room.

 

[Randy Holmes-Farley]

Kalkwasser might work, but only if the increased precipitation and biological demand from the high pH match or exceed the dosed amount, which it may not.

Thus, I would not presume this is a good plan when there is little to no alk demand.

 

[Calm Blue Ocean]

Kalkwasser might work, but only if the increased precipitation and biological demand from the high pH match or exceed the dosed amount, which it may not.

Thus, I would not presume this is a good plan when there is little to no alk demand.

Ah yes, the answer I think I knew deep down but hoped wasn't the answer. Time to figure out how to jam a real skimmer into my AIO!

 

[vtecintegra]

That could be another consideration...switch to a salt with lower alk to give me some wiggle room.

At first I thought that was an idea. I'm somewhat in the same boat using IO while trying to dose kalk for pH.

Flaw with low alk salt: You are going to dose up to your desired level, then be right back to square one. The controlling factor is actually how much alk is being used. It controls how much kalk can be added, not where you are starting from. In my quest and not testing enough, I've ran my alk up to 11.5 and had to stop the kalk while I let it fall slowly. I shoot for 9.5 which is close to what I see with IO.

 

[Calm Blue Ocean]

At first I thought that was an idea. I'm somewhat in the same boat using IO while trying to dose kalk for pH.

Flaw with low alk salt: You are going to dose up to your desired level, then be right back to square one. The controlling factor is actually how much alk is being used. It controls how much kalk can be added, not where you are starting from. In my quest and not testing enough, I've ran my alk up to 11.5 and had to stop the kalk while I let it fall slowly. I shoot for 9.5 which is close to what I see with IO.

Yeah, I kinda facepalmed after I posted this. Lower alk salt won't magically make my tank consume alk, which is the issue. Doh.

 

[Calm Blue Ocean]

A quick follow up question. What kind of alk consumption do I want to see for kalk to be a practical solution?

 

[Randy Holmes-Farley]

A quick follow up question. What kind of alk consumption do I want to see for kalk to be a practical solution?

Depends on your evaporation rate.

Adding 1% of the tank volume daily with saturated limewater boosts alk by about 1.1 dKH.

 

[homer1475]

In regards to high ALK salts....

You do know you can bring the ALK down by simply adding an acid such as muriatic acid, or seachems acid buffer? This should never be added to a tank with live inhabitants, but can be used in your NSW.

Been doing it for years in IO to bring it down to my level of 7.5DKH.

 

[Outlaw4640]

I have found that Kalkwasser provides a nice stable pH boost when slowly dripped into your system. However, this requires either a kalk reactor or a simple gravity drip feed.

If you go the ATO option, your pH and Alk dosing will be subject to you evaporation rate and may be less stable and harder to hit your alk consumption rate.

If you do go the ATO route, I suggest you measure your evaporation rate and your Alk consumption for your tank. Then spike your ATO with the amount of Kalk that will keep your tank Alk stable.

Thanks for the info. I was hovering around 7.6- 7.8 ph. Want to get it between 8.1 - 8.3. Got my jug already to make a kalkwasser dripper. Then I can finally add coral !

 

[arking_mark]

Thanks for the info. I was hovering around 7.6- 7.8 ph. Want to get it between 8.1 - 8.3. Got my jug already to make a kalkwasser dripper. Then I can finally add coral !

7.6 ph is not a number your tank can reasonably have with decent aeration. Your measurement device is probably wrong.

Post in thread 'Aquarium pH Distilled' https://www.reef2reef.com/threads/aquarium-ph-distilled.853474/post-9330359