Tank crushing alk

[ThePurple12]

The same thing is happening with my 3-year-old 125g. It'll drop down to 5 over just a few days. All I have are several SPS frags and 2 LPS. There's no way the corals are consuming that much so quickly. I do have lots of coralline, but still, that's a big drop.

 

[Aere]

The same thing is happening with my 3-year-old 125g. It'll drop down to 5 over just a few days. All I have are several SPS frags and 2 LPS. There's no way the corals are consuming that much so quickly. I do have lots of coralline, but still, that's a big drop.

Out of curiosity what are you using to raise alk?

 

[ThePurple12]

Baking soda

 

[ThePurple12]

Maybe @Randy Holmes-Farley can help us.

 

[Sisterlimonpot]

How soon after adding alk to the tank are you testing? And are you adding alk in the same chamber that you're pulling water to test?

 

[Aere]

How soon after adding alk to the tank are you testing? And are you adding alk in the same chamber that you're pulling water to test?

Seperate chamber. And I have a trident so it tests all day long heh. Which I verify with other tests.

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure there is anything "wrong", but if you are using sodium carbonate for dosing, switching to sodium bicarbonate will lower pH and thus reduce the potential for precipitation.

Do not do things to raise pH, such as a CO2 scrubber.

Is there any coralline growth? A soft coral tank with coralline growth can consume 2 dKH per day.

 

[Saltyreef]

You should do a consumption trend over 5 days to see your daily average consumption.

Then dose based on that.

This will solve your problems most likely.

 

[Aere]

I'm not sure there is anything "wrong", but if you are using sodium carbonate for dosing, switching to sodium bicarbonate will lower pH and thus reduce the potential for precipitation.

Do not do things to raise pH, such as a CO2 scrubber.

Is there any coralline growth? A soft coral tank with coralline growth can consume 2 dKH per day.

Appears go be the beginning of coralline yes. And I had a co2 scrubber on. Well I do. Should I unhook it? Whats the theory there?

 

[Randy Holmes-Farley Verified Community Expert]

Appears go be the beginning of coralline yes. And I had a co2 scrubber on. Well I do. Should I unhook it? Whats the theory there?

High pH is by far the biggest driver of precipitation of calcium carbonate in a reef tank as it converts the bicarbonate into carbonate.

A 0.3 pH unit rise in pH is the same as a doubling of alkalinity (say, 7 to 14 dKH) or calcium (say, 420 to 840 ppm) in terms of potential for precipitation.

 

[Aere]

High pH is by far the biggest driver of precipitation of calcium carbonate in a reef tank as it converts the bicarbonate into carbonate.

A 0.3 pH unit rise in pH is the same as a doubling of alkalinity (say, 7 to 14 dKH) or calcium (say, 420 to 840 ppm) in terms of potential for precipitation.

Is precipitation bad for the tank inhabitants?

 

[Randy Holmes-Farley Verified Community Expert]

Is precipitation bad for the tank inhabitants?

Not necessarily. I think it is happening all the time in all reef tanks. What changes is the rate and possibly where it happens.

Hardening sand is not optimal.

These are the deposits where I doses limewater that sometimes dripped onto the sump side instead of into the strong stream of flow:

http://reefkeeping.com/issues/2005-07/rhf/index.htm

Figure 4. When limewater drips onto surfaces, such as the sides of a sump, precipitation of calcium carbonate takes place. The off-white coloration probably comes from metals such as iron binding to the calcium carbonate surface in the place of calcium.

 

[Aere]

Not necessarily. I think it is happening all the time in all reef tanks. What changes is the rate and possibly where it happens.

Hardening sand is not optimal.

These are the deposits where I doses limewater that sometimes dripped onto the sump side instead of into the strong stream of flow:

http://reefkeeping.com/issues/2005-07/rhf/index.htm

Figure 4. When limewater drips onto surfaces, such as the sides of a sump, precipitation of calcium carbonate takes place. The off-white coloration probably comes from metals such as iron binding to the calcium carbonate surface in the place of calcium.

Thank you so much for your help. That all makes sense

 

[adobo]

Do not do things to raise pH, such as a CO2 scrubber.

Wait, what? Is this advice for the OP and his specific circumstance or is this generic advice? I have a tank that likes to drift down to 7.8 pH. Not sure how low it would go without my intervention. Opening windows in the room helps but it is a huge hassle for several reasons (security, heat wave, outside air quality issues, etc.).

I'm using a CO2 scrubber to try and maintain pH between 8.15 and 8.25. I haven't noticed hardening of my sand bed yet. I do not know what the tank's Alk or Ca levels are as the tank is young, it doesn't have any stony corals yet and coralline algae is just barely starting to grow. As such, I haven't felt compelled to test Ca or Alk. I was expecting weekly water changes to be sufficient to replenish whatever is being used up and to dilute whatever is accumulating.

If 7.8 pH is better than intervening with a CO2 scrubber to maintain 8.2ish pH, I'd like to know.

OP, sorry for the off topic inquiry in your thread.

 

[Aere]

Wait, what? Is this advice for the OP and his specific circumstance or is this generic advice? I have a tank that likes to drift down to 7.8 pH. Not sure how low it would go without my intervention. Opening windows in the room helps but it is a huge hassle for several reasons (security, heat wave, outside air quality issues, etc.).

I'm using a CO2 scrubber to try and maintain pH between 8.15 and 8.25. I haven't noticed hardening of my sand bed yet. I do not know what the tank's Alk or Ca levels are as the tank is young, it doesn't have any stony corals yet and coralline algae is just barely starting to grow. As such, I haven't felt compelled to test Ca or Alk. I was expecting weekly water changes to be sufficient to replenish whatever is being used and to dilute whatever is accumulating.

If 7.8 pH is better than intervening with a CO2 scrubber to maintain 8.2ish pH, I'd like to know.

OP, sorry for the off topic inquiry in your thread.

I think more or less it's up to you. I notice a difference for sure in alkalinity with and without the scrubber going. I tested it for a day. With it on im dropping alk like a rock, so u have to dos more, without it on it's less im having to dos.

 

[wranodj]

Try kalkwasser in you ATO, 1 teaspoon per gallon max until you stabilize. Will raise pH, however. May help stabilize. Then when your tank exceeds what kalkwasser provides you can dose. Without lps or sps should be plenty.

 

[Reef GE]

Not necessarily. I think it is happening all the time in all reef tanks. What changes is the rate and possibly where it happens.

Hardening sand is not optimal.

These are the deposits where I doses limewater that sometimes dripped onto the sump side instead of into the strong stream of flow:

http://reefkeeping.com/issues/2005-07/rhf/index.htm

Figure 4. When limewater drips onto surfaces, such as the sides of a sump, precipitation of calcium carbonate takes place. The off-white coloration probably comes from metals such as iron binding to the calcium carbonate surface in the place of calcium.

What does hardening sand signify? People talk about hardening sand but I haven’t yet seen the explanation of why this is not good. What causes it? How to avoid it?

 

[Shaun Sweeney]

My system (400 gal.) has been stable at 7.7 for years but dkh has been dropping lately. I've doubled my dosing and still slipped a bit - down to 7.3. Manually raised it today and changed my alk mix so we'll see if I can settle it out by tomorrow. Strange.

 

[blasterman]

Hello.

My tank is 2 months old. I have 10 fish. And a cleanup crew. And about 15 frags. Mostly zoas. A couple acans. And a birdsnest.

My alkalinity consumption seems strange.

I dosed last night at 10pm. Brought alk to 9, CA to 460 and mg to 1400.

This morning at 8am alk was 7.67 verified with 3 separate tests including trident.

These drops are pretty normal as of late.

Does this seem normal? And can I keep dosing to 9? I know its not needed right now. But I would like to stay in the habit of stability.

300 gallon tank, 40 gallons or so in the sump.

Young tanks destroy alk as its used as building blocks for bacteria and algae beds.

I've had many 2month old frag tanks eat 2dKH of alk a night. When they finally stabilize at 3-4 months alk slows down and then balances with calcium consumption.

Add some fish and alk consumption goes up as its consumed via the nitrogen cycle to adjust to the increased bioload. Mature tanks with no SPS might not see alk move much at all.

This is why reef crystals has high default alk.

Nothing odd here, its just I start up a lot of tanks and could write a script for all this. Alk is cheap....its baking doda.

 

[Randy Holmes-Farley Verified Community Expert]

Wait, what? Is this advice for the OP and his specific circumstance or is this generic advice?

It is advice just for someone trying to reduce abiotic precipitation of calcium carbonate.

pH is a big driver of the process.

if abiotic precipitation is not a problem that is looking for an answer, then such methods are fine.