Why am I unable to change the pH and Alkalinity of my reef tanks

[optimisticdingo]

Hello everyone! I've got 2 reef tanks currently set up a 40-gallon breeder and a 10-gallon Fluval flex that I have upgraded the lighting on. The 40g has been set up for four months while the 10g has been set up since January. Both have had stable chemistry but I'm currently unhappy with my pH and kH levels in the tanks. Every time I test the pH in both tanks it is at 8.0 and the kH is around 11. I dose aquavitro eight.four and aquavitro balance to try and raise the pH to around 8.3-8.4 but, while the pH levels rise after dosing they quickly fall back to 8.0 by the next day. I know that low pH can sometimes be caused by low calcium and magnesium levels, however, when testing these levels I've found that my calcium stays around 400 and my magnesium stays around 1300 with my current dosing schedule.

As far as kH is concerned I also feel that my usual level of 11 is too high given that the typical range of kH for a reef tank, to my knowledge, is between 8-11dkH. I would rather my kH be around 9-10 to have some wiggle room in case something were to cause it to rise or fall. I do water changes weekly, however, even after doing a water change, the kH is still at the same level.

Why is it that I can't seem to get these levels to change? I suppose this isn't a horrible problem to have given that they are stable but I feel that they could be better. I don't like my pH being at the absolute low end of the spectrum and my kH being at the absolute high end of the spectrum since they neither give me any buffer in the event that something goes wrong. Perhaps my logic is flawed, and if so, I would love to be educated more. I've absolutely loved getting into the reefing hobby and would love to learn as much about the chemistry of the water as I can.

 

[mdb_talon]

Your PH is far from the "absolute low". For starters you need to see what your actual range of PH is. You mention always 8, but that is highly unlikely it does not go up/down by at least .2 through the day. Test multiple times a day. Specifically at the very end of your light cycle(should be highpoint) and right before lights come on(should be lowpoint). Even if using reverse lit refugium i expect you will still see some range. As for KH being higher than you want that is likely because you are dosing alkalinity(the aquavitro 8.4). If 8 is the highpoint and you get down to 7.8 that is on the lowside maybe, but not worth hosing up your alk chasing a higher number. Thats also ehat many sucessful tanks run at.

My suggestion is stop dosing alk products based off your ph value. Figure out the real range of your ph when at desired alk level. Then if you feel the need to address ph check for water aeration tests to see if it is a co2 issue in which case there are ways to raise it.

 

[Spare time]

Honestly 11KH isn't bad. I run my tank around that. I have even had it at 14 without anything appearing upset (that was temporary though as it was an accident). Many salt mixes at at 12 ish.

 

[arking_mark]

Hello everyone! I've got 2 reef tanks currently set up a 40-gallon breeder and a 10-gallon Fluval flex that I have upgraded the lighting on. The 40g has been set up for four months while the 10g has been set up since January. Both have had stable chemistry but I'm currently unhappy with my pH and kH levels in the tanks. Every time I test the pH in both tanks it is at 8.0 and the kH is around 11. I dose aquavitro eight.four and aquavitro balance to try and raise the pH to around 8.3-8.4 but, while the pH levels rise after dosing they quickly fall back to 8.0 by the next day. I know that low pH can sometimes be caused by low calcium and magnesium levels, however, when testing these levels I've found that my calcium stays around 400 and my magnesium stays around 1300 with my current dosing schedule.

As far as kH is concerned I also feel that my usual level of 11 is too high given that the typical range of kH for a reef tank, to my knowledge, is between 8-11dkH. I would rather my kH be around 9-10 to have some wiggle room in case something were to cause it to rise or fall. I do water changes weekly, however, even after doing a water change, the kH is still at the same level.

Why is it that I can't seem to get these levels to change? I suppose this isn't a horrible problem to have given that they are stable but I feel that they could be better. I don't like my pH being at the absolute low end of the spectrum and my kH being at the absolute high end of the spectrum since they neither give me any buffer in the event that something goes wrong. Perhaps my logic is flawed, and if so, I would love to be educated more. I've absolutely loved getting into the reefing hobby and would love to learn as much about the chemistry of the water as I can.

Let's start with pH. Your tank will find a pH balance based on the CO2 levels in the air around your tank. Generally speaking the CO2 levels in your house are higher than natural levels found outdoors. This is do to people, pets, etc...that produce CO2 in a more sealed environment.

You can easily test for this using a cup aeration test.

 

[Randy Holmes-Farley]

Hello everyone! I've got 2 reef tanks currently set up a 40-gallon breeder and a 10-gallon Fluval flex that I have upgraded the lighting on. The 40g has been set up for four months while the 10g has been set up since January. Both have had stable chemistry but I'm currently unhappy with my pH and kH levels in the tanks. Every time I test the pH in both tanks it is at 8.0 and the kH is around 11. I dose aquavitro eight.four and aquavitro balance to try and raise the pH to around 8.3-8.4 but, while the pH levels rise after dosing they quickly fall back to 8.0 by the next day. I know that low pH can sometimes be caused by low calcium and magnesium levels, however, when testing these levels I've found that my calcium stays around 400 and my magnesium stays around 1300 with my current dosing schedule.

As far as kH is concerned I also feel that my usual level of 11 is too high given that the typical range of kH for a reef tank, to my knowledge, is between 8-11dkH. I would rather my kH be around 9-10 to have some wiggle room in case something were to cause it to rise or fall. I do water changes weekly, however, even after doing a water change, the kH is still at the same level.

Why is it that I can't seem to get these levels to change? I suppose this isn't a horrible problem to have given that they are stable but I feel that they could be better. I don't like my pH being at the absolute low end of the spectrum and my kH being at the absolute high end of the spectrum since they neither give me any buffer in the event that something goes wrong. Perhaps my logic is flawed, and if so, I would love to be educated more. I've absolutely loved getting into the reefing hobby and would love to learn as much about the chemistry of the water as I can.

Sadly, you've been suckered by the misleading claims of Aquavitro.

lesson: do not believe manufacturer claims.

The pH in your tank is ONLY determined by the alkalinity and the carbon dioxide level in the water. Most often, that CO2 level is driven by the CO2 level in your home air, biological processes int eh aquarium (photosynthesis and respiration) and the addition of alkalintiy additives that can add or remove CO2.

Aquavitro 8.4 (mostly sodium bicarbonate and some sodium carbonate) is an alk supplement that has a small pH raising effect. You can get a bigger pH raising effect using just sodium carbonate and a n even bigger effect from using sodium hydroxide.

That said, pH 8.0 is fine and I would not agionize over raising it.

 

[arking_mark]

Sadly, you've been suckered by the misleading claims of Aquavitro.

lesson: do not believe manufacturer claims.

The pH in your tank is ONLY determined by the alkalinity and the carbon dioxide level in the water. Most often, that CO2 level is driven by the CO2 level in your home air, biological processes int eh aquarium (photosynthesis and respiration) and the addition of alkalintiy additives that can add or remove CO2.

Aquavitro 8.4 (mostly sodium bicarbonate and some sodium carbonate) is an alk supplement that has a small pH raising effect. You can get a bigger pH raising effect using just sodium carbonate and a n even bigger effect from using sodium hydroxide.

That said, pH 8.0 is fine and I would not agionize over raising it.

@Randy Holmes-Farley I have added to my reefkeeping mantra:

Do not believe manufacturer claims

 

[optimisticdingo]

Sadly, you've been suckered by the misleading claims of Aquavitro.

lesson: do not believe manufacturer claims.

The pH in your tank is ONLY determined by the alkalinity and the carbon dioxide level in the water. Most often, that CO2 level is driven by the CO2 level in your home air, biological processes int eh aquarium (photosynthesis and respiration) and the addition of alkalintiy additives that can add or remove CO2.

Aquavitro 8.4 (mostly sodium bicarbonate and some sodium carbonate) is an alk supplement that has a small pH raising effect. You can get a bigger pH raising effect using just sodium carbonate and a n even bigger effect from using sodium hydroxide.

That said, pH 8.0 is fine and I would not agionize over raising it.

So I was at my LFS today and asking about this and was told that for my SPS corals a kH of 12 was too high. I was also told that I shouldn't be using either Eight.Four or Balance when keeping corals. Is this true and if so what should I be using instead?

 

[arking_mark]

So I was at my LFS today and asking about this and was told that for my SPS corals a kH of 12 was too high. I was also told that I shouldn't be using either Eight.Four or Balance when keeping corals. Is this true and if so what should I be using instead?

Eight.Four and Balance are basically both Alk supplement that will increase pH.

Generally speaking one should only use these to adjust your Alk or in conjunction with a balanced amount of Ca. A tank will consume Alk and Ca in near equal amounts.

 

[mdb_talon]

Sadly, you've been suckered by the misleading claims of Aquavitro.

lesson: do not believe manufacturer claims.

The pH in your tank is ONLY determined by the alkalinity and the carbon dioxide level in the water. Most often, that CO2 level is driven by the CO2 level in your home air, biological processes int eh aquarium (photosynthesis and respiration) and the addition of alkalintiy additives that can add or remove CO2.

Aquavitro 8.4 (mostly sodium bicarbonate and some sodium carbonate) is an alk supplement that has a small pH raising effect. You can get a bigger pH raising effect using just sodium carbonate and a n even bigger effect from using sodium hydroxide.

That said, pH 8.0 is fine and I would not agionize over raising it.

Maybe a stupid question, but do some alk boosters increase ph more than others because they have more impact on co2 levels in the tank?

 

[arking_mark]

Maybe a stupid question, but do some alk boosters increase ph more than others because they have more impact on co2 levels in the tank?

I'll provide you some more info based on my experience.

Many aquarist run successful tanks with stability. A stable pH somewhere between 7.8 - 8.5 is considered fine. Same goes with some stable dKH between Alk 7 - 12.

pH tends to be lower than natural seawater because of CO2 levels in your house.

dKH levels drop due to near equal consumption of Alk and Ca though your corals and Calcium Carbonate precipitation in your tank. This consumption is very low in newer tanks and tanks that have little coral growing.

At some point, as you tank matures and more coral is growing, water changes will not keep up with you Alk/Ca consumption and you will need to supplement your tank with balanced dosing.

Many balanced supplements can also provide a pH boost. Higher pH is desirable as it has been linked to faster coral growth.

There are way too many types of dosing products and regiments. However, many will start with a Kalkwasser drip, ATO, or doser as it provides a balanced Alk/Ca and raises pH. The dosing is typically limited to your evaporation rate of the tank. Then reefers will graduate to 2 or 3 part dosing regiments such as the Balling Methoded or high-pH 2-part DIY solutions.

pH can also be raised in a tank by aerating a tank with outside air or CO2 scrubbed air. This is typically done with a skimmer. It should be noted that a skimmer running on house air will more quickly bring down your pH to equilibrium in your house. So using a high-ph Alk/Ca supplement will be less effective with a skimmer that is working to keep your tank in equilibrium with your higher CO2 indoor air.

 

[mdb_talon]

I'll provide you some more info based on my experience.

Many aquarist run successful tanks with stability. A stable pH somewhere between 7.8 - 8.5 is considered fine. Same goes with some stable dKH between Alk 7 - 12.

pH tends to be lower than natural seawater because of CO2 levels in your house.

dKH levels drop due to near equal consumption of Alk and Ca though your corals and Calcium Carbonate precipitation in your tank. This consumption is very low in newer tanks and tanks that have little coral growing.

At some point, as you tank matures and more coral is growing, water changes will not keep up with you Alk/Ca consumption and you will need to supplement your tank with balanced dosing.

Many balanced supplements can also provide a pH boost. Higher pH is desirable as it has been linked to faster coral growth.

There are way too many types of dosing products and regiments. However, many will start with a Kalkwasser drip, ATO, or doser as it provides a balanced Alk/Ca and raises pH. The dosing is typically limited to your evaporation rate of the tank. Then reefers will graduate to 2 or 3 part dosing regiments such as the Balling Methoded or high-pH 2-part DIY solutions.

pH can also be raised in a tank by aerating a tank with outside air or CO2 scrubbed air. This is typically done with a skimmer. It should be noted that a skimmer running on house air will more quickly bring down your pH to equilibrium in your house. So using a high-ph Alk/Ca supplement will be less effective with a skimmer that is working to keep your tank in equilibrium with your higher CO2 indoor air.

Thanks for the in-depth response i been dosing for decades though just trying to get to actually get the answer to why sodium hydroxide for example has a bigger impact on ph that does sodium bicarbonate. I have always assumed they impact the co2 in different ways, but looking to get confirmation.

 

[blasterman]

Eight.Four and Balance are basically both Alk supplement that will increase pH.

Generally speaking one should only use these to adjust your Alk or in conjunction with a balanced amount of Ca. A tank will consume Alk and Ca in near equal amounts.

Completely and utterly totally false. Stop giving bad advice.

How many dozens of posts per week do we get in this forum with people having calcium and alk totally out of whack because they've bought into this two part kool aid?

I will give you a refresher: alk and calcium are only consumed in a defined and consistent ratio *IF* you have a large amount of fast growing SPS, clams, etc. Alk in most tanks without large amounts of calcifying coral *NEVER* tracks consistently with calcium. Too many biologic processes eat alk.

Again, we get hordes of posts with people having dKH diving daily with little calcium changes. Stop pushing the marketing of two parts and stop calling my phone trying to sell me car warranties.

 

[arking_mark]

Thanks for the in-depth response i been dosing for decades though just trying to get to actually get the answer to why sodium hydroxide for example has a bigger impact on ph that does sodium bicarbonate. I have always assumed they impact the co2 in different ways, but looking to get confirmation.

I'll leave that to the chemists....but you can look up those impacts to pH.

 

[arking_mark]

Completely and utterly totally false. Stop giving bad advice.

How many dozens of posts per week do we get in this forum with people having calcium and alk totally out of whack because they've bought into this two part kool aid?

I will give you a refresher: alk and calcium are only consumed in a defined and consistent ratio *IF* you have a large amount of fast growing SPS, clams, etc. Alk in most tanks without large amounts of calcifying coral *NEVER* tracks consistently with calcium. Too many biologic processes eat alk.

Again, we get hordes of posts with people having dKH diving daily with little calcium changes. Stop pushing the marketing of two parts and stop calling my phone trying to sell me car warranties.

I'll just reference the science....but generally speaking there is a much smaller quantity of Alk than Ca in saltwater so small changes in Ca are much bigger swings in Alk.

http://reefkeeping.com/issues/2004-12/rhf/index.php

For ALL practical purposes Alk/Ca are consumed equally with the occasional need to rebalance.

 

[homer1475]

Completely and utterly totally false. Stop giving bad advice.

How many dozens of posts per week do we get in this forum with people having calcium and alk totally out of whack because they've bought into this two part kool aid?

I will give you a refresher: alk and calcium are only consumed in a defined and consistent ratio *IF* you have a large amount of fast growing SPS, clams, etc. Alk in most tanks without large amounts of calcifying coral *NEVER* tracks consistently with calcium. Too many biologic processes eat alk.

Again, we get hordes of posts with people having dKH diving daily with little calcium changes. Stop pushing the marketing of two parts and stop calling my phone trying to sell me car warranties.

No the problem isn't that are aren't being consumed in ratio, it's just the relatively small drop in CAL, when compared to the large drop in ALK, typically isn't picked up by our hobby grade test kits.

I dose 2 part in equal parts, but based off ALK. My CAL never changes when tested, yet I'm always adding 135ml daily, same as ALK that fluctuates a bit. Yes there are small changes that can effect the ratio, but typically they are used in a very consistent ratio. Early on, sure there are biological processes that eat ALK, but once the tank is cycled, that shouldn't be an issue every again.

You might want to do a little reading(known as research) before claiming people are putting out lies.

Ever wonder why kalk is so popular? because it add ALK and CAL back into the tank at a balanced ratio.

 

[((FORDTECH))]

Completely and utterly totally false. Stop giving bad advice.

How many dozens of posts per week do we get in this forum with people having calcium and alk totally out of whack because they've bought into this two part kool aid?

I will give you a refresher: alk and calcium are only consumed in a defined and consistent ratio *IF* you have a large amount of fast growing SPS, clams, etc. Alk in most tanks without large amounts of calcifying coral *NEVER* tracks consistently with calcium. Too many biologic processes eat alk.

Again, we get hordes of posts with people having dKH diving daily with little calcium changes. Stop pushing the marketing of two parts and stop calling my phone trying to sell me car warranties.

This is the boat I’m in. Without hyjacking this guys thread let me ask you a question about this. I have 250 gallon tank with 50 ml of alk added daily and 0 calcuim. Alk is solid steady 7.5 and cal is solid stead 460 . I do daily auto water changes aswell. Question is what do you think will happen if I started to dose the equal 2 part of calcium of 50ml daily with my 50ml of alk? Or should I just continue to only dose alk for long time till calcium can’t kept up with just auto water changes no more and starts to drop?

 

[homer1475]

This is the boat I’m in. Without hyjacking this guys thread let me ask you a question about this. I have 250 gallon tank with 50 ml of alk added daily and 0 calcuim. Alk is solid steady 7.5 and cal is solid stead 460 . I do daily auto water changes aswell. Question is what do you think will happen if I started to dose the equal 2 part of calcium of 50ml daily with my 50ml of alk? Or should I just continue to only dose alk for long time till calcium can’t kept up with just auto water changes no more and starts to drop?

In your case, your WC is keeping up with cal consumption. I would just continue to dose alk until the cal starts to fall.

 

[arking_mark]

This is the boat I’m in. Without hyjacking this guys thread let me ask you a question about this. I have 250 gallon tank with 50 ml of alk added daily and 0 calcuim. Alk is solid steady 7.5 and cal is solid stead 460 . I do daily auto water changes aswell. Question is what do you think will happen if I started to dose the equal 2 part of calcium of 50ml daily with my 50ml of alk? Or should I just continue to only dose alk for long time till calcium can’t kept up with just auto water changes no more and starts to drop?

Please read this article:

http://reefkeeping.com/issues/2004-12/rhf/index.php

It will answer your question.

 

[Randy Holmes-Farley]

Maybe a stupid question, but do some alk boosters increase ph more than others because they have more impact on co2 levels in the tank?

Definitely.

The four alkalinity supplements typically used are:

1. acetate or formate (usually in all in one products). They raise CO2 and lower pH
2. bicarbonate. Very slight pH lowering from CO2 addition.
3. carbonate. Substantial pH raising from CO2 "consumption"
4. hydroxide. Largest pH boost from most CO2 "consumption"

Products like 8.4 and many similar "buffers" are just a mixture of bicarbonate and carbonate.

 

[((FORDTECH))]

Please read this article:

http://reefkeeping.com/issues/2004-12/rhf/index.php

It will answer your question.

Ok so I did read the whole article but still not sure how I should proceed. I believe The article is saying I should be adding equal parts alk and cal. But if I add the 50ml daily of cal along with the daily water changes calcium goes up into the 500s. This is why I stopped dosing cal to have a steady cal of 460. I’m still confused as to what would be best for my system. Most likely will just keep only dosing alk.