Constant Low Alk in newish tank

[Aaron75]

So I have a 15g which I know will lead to some instability but this one is stumping me. Randy kind of started me on the topic so I'd like to discuss further. My Alk stays around 6. Yesterday i measured and it was 4.9. Did a 20-25% water change and 24 hours later it is 5.7. Using reef Crystals, fresh mix was 11.2. Now where Randy lost me is about a correlation with nitrates and Alk. And another thing about precipitation. Can I dose All for Reef and be fine, or is there more to it? Ultimately I'd like a full break down on cause and effects and just to learn what I can/ should do.

 

[Lemons]

So I have a 15g which I know will lead to some instability but this one is stumping me. Randy kind of started me on the topic so I'd like to discuss further. My Alk stays around 6. Yesterday i measured and it was 4.9. Did a 20-25% water change and 24 hours later it is 5.7. Using reef Crystals, fresh mix was 11.2. Now where Randy lost me is about a correlation with nitrates and Alk. And another thing about precipitation. Can I dose All for Reef and be fine, or is there more to it? Ultimately I'd like a full break down on cause and effects and just to learn what I can/ should do.

From my limited chemistry knowledge i think it takes some alk (bicarbonates) in the nitrification process.

Is your sand clumping/ turning into rocks??? What kinda bioload do you have?? Lots of corals?? Also what are ya using for testing??

 

[flatlander93]

Free bump as I’m dealing with about the same thing. 5.3 here and can’t raise with water change or all for reef. Just ordered two part to boost levels including magnesium as that has a strong relationship with all.

 

[thmaster00]

From my limited chemistry knowledge i think it takes some alk (bicarbonates) in the nitrification process.

Is your sand clumping/ turning into rocks??? What kinda bioload do you have?? Lots of corals?? Also what are ya using for testing??

Hi, I was reading the comments and saw your questions. What does it mean if my sand is clumping up?

 

[Lemons]

Hi, I was reading the comments and saw your questions. What does it mean if my sand is clumping up?

If your sand is clumping up that could mean that you are experincing a deposition event, aka your alk and calcium are outta wack and dont want to stay in solution so they start to form crystals. And our sandbeds are the perfect seeding spots for these crystals

 

[Lemons]

If your sand is clumping up that could mean that you are experincing a deposition event, aka your alk and calcium are outta wack and dont want to stay in solution so they start to form crystals. And our sandbeds are the perfect seeding spots for these crystals

Maybe test your other parameters

Ca,Mag,pH just to kinda get a base line for whats goin on...

When i had my percipitation event i was dosing 61ml of brightwell alk into a 2month old LPS tank lol

 

[thmaster00]

If your sand is clumping up that could mean that you are experincing a deposition event, aka your alk and calcium are outta wack and dont want to stay in solution so they start to form crystals. And our sandbeds are the perfect seeding spots for these crystals

Wow! You are right. I just tested my parameters. My alk is at 6.4 and cal is over 500. Thank you for your insight!

 

[Aaron75]

From my limited chemistry knowledge i think it takes some alk (bicarbonates) in the nitrification process.

Is your sand clumping/ turning into rocks??? What kinda bioload do you have?? Lots of corals?? Also what are ya using for testing??

Sand is not clumpy. I have gsp on the wall, 1 single head splitting torch, 1 5 head micro hammer, 12 total heads of zoas, and 1 1" homewrecker that is surprisingly doing well. Using new Hanna checker, changed reagents and got same results. I'd say medium bioload, I do have to dose nitrates to keep them up.

 

[Lemons]

Sand is not clumpy. I have gsp on the wall, 1 single head splitting torch, 1 5 head micro hammer, 12 total heads of zoas, and 1 1" homewrecker that is surprisingly doing well. Using new Hanna checker, changed reagents and got same results. I'd say medium bioload, I do have to dose nitrates to keep them up.

Hmm not alot of calcifying corals... kinda odd that it'd consume 1.7dkh daily but then again 15 gallons is not alot of buffer

Id say keep an eye on your sand and other perameters, and maybe check your Mag? Low mag makes it hard to maintain the other two :)

Ps 4.9 to 11.2 is a massive alk swing! Try to raise it slowly

 

[Aaron75]

This is what I've got

 

[Aaron75]

Hmm not alot of calcifying corals... kinda odd that it'd consume 1.7dkh daily but then again 15 gallons is not alot of buffer

Id say keep an eye on your sand and other perameters, and maybe check your Mag? Low mag makes it hard to maintain the other two :)

I'll test mag and calcium whenever I get those tests and see what I've got. Thanks.

 

[Lemons]

This is what I've got

Looks good so far! Love the rock nems

 

[Randy Holmes-Farley Verified Community Expert]

So there is no sign of sand hardening, or precipitation on pump impellers and heaters?

How are you measuring alk? 4.9 dKH is extraordinarily low and may be an error. Try the kit on some new salt water.

 

[Aaron75]

So there is no sign of sand hardening, or precipitation on pump impellers and heaters?

How are you measuring alk? 4.9 dKH is extraordinarily low and may be an error. Try the kit on some new salt water.

Hanna tester, tester is new. Used reagent that came with it as well as a new one and got identical results. Tested newly mixed reef Crystals and it was 11.2

 

[bee144]

So the one person on the thread has high calcium. Cal and Alk are directly related. When dosing alk, it’ll make your cal go down and vice versa.

I’ve also read that items like Marine Pure blocks can absorb alk? (Not sure how true that is) but if true, I believe it might have been my cause.

Anyways, my tank is 4 months old and I just setup my trident to get ready for my first corals. My alk was around 5. I’ve setup my Versa dosing pumps for cal, alk, and mag and dosing has allowed me to hit the numbers. Yesterday, my average alk was 8.14.

 

[Aaron75]

@Randy Holmes-Farley @Lemons
So here is my full test board:

Ph: 8.0-8.2 (Api)
Alk: 5.1 (Hanna) down from 5.7 24 hrs ago
Nitrates: 12.9 Hanna
Phosphates: .05 Hanna ULR
Magnesium: 1500+ (Salifert)
Calcium: 500 (Salifert)

 

[Randy Holmes-Farley Verified Community Expert]

I’ve also read that items like Marine Pure blocks can absorb alk? (Not sure how true that is) but if true, I believe it might have been my cause.

FWIW, I haven't heard that, but unless one is precipitating calcium carbonate onto them, they cannot bind enough alk to be a significant issue.

 

[Icryhard]

From my limited chemistry knowledge i think it takes some alk (bicarbonates) in the nitrification process.

Is your sand clumping/ turning into rocks??? What kinda bioload do you have?? Lots of corals?? Also what are ya using for testing??

Interesting. My sand indeed does clump / turn into rock-like. However not for long cuz I have 2 of those gobbies(?) who eat my sand and keep it clean. What is this process called and where can I read more about it?

 

[Randy Holmes-Farley Verified Community Expert]

Interesting. My sand indeed does clump / turn into rock-like. However not for long cuz I have 2 of those gobbies(?) who eat my sand and keep it clean. What is this process called and where can I read more about it?

It is most likely precipitation of calcium carbonate.

What is that Precipitate in My Reef Aquarium? by Randy Holmes-Farley - Reefkeeping.com

I do not specifically address sand in the article, but the article details the issue.

 

[Aaron75]

So here is my full test board:

Ph: 8.0-8.2 (Api)
Alk: 5.1 (Hanna) down from 5.7 24 hrs ago
Nitrates: 12.9 Hanna
Phosphates: .05 Hanna ULR
Magnesium: 1500+ (Salifert)
Calcium: 500 (Salifert)

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