Lowering Alkalinity

Sound · 10/31/2009, 11:05 AM

Hey Guys,

My parameters are as follows:

PH 8.2
Am 0
Nitrite 0
Nitrates 50ppm (high I know)
Calcium 440
Alkalinity 14dkh

How do I lower my Alk? It seems like this is the most complicated parameter to adjust and everyone's opinion is different. Things range from massive water changes to doing absolutely nothing and wait for it to go down? Is 14 dkh that bad, or are my nitrates more somehting to worry about?

jenjen · 10/31/2009, 11:56 AM

Here's an article on alkalinity that may be helpful:

http://www.wetwebmedia.com/alkalinity.htm

I wouldn't worry too much about trying to lower it just yet. I'd be more inclined to get all your other parameters in check, and confirm that your reading is correct for alk before you do anything to try and adjust it.

rbnice1 · 10/31/2009, 11:58 AM

Depends on whats in the tank. If it is a sps tank I would say nitrates are your worst problem. Do water changes to bring your nitrates down and it will bring your alk down as well.

Randy Holmes-Farley · 10/31/2009, 01:51 PM

How do I lower my Alk? It seems like this is the most complicated parameter to adjust and everyone's opinion is different.

The ways to lower alkalinity are not opinion, but which one you choose will possibly be so.

Direct acid addition, using muriatic acid/hydrochloric acid or sulfuric acid works perfectly and instantly, but is almost certainly too risky for an existing reef tank at 14 dKH, so I'd avoid that one.

Adding so much calcium as to drive down alkalinity by precipitating calcium carbonate will drive calcium very high and will coat pumps and such with calcium carbonate, so that's a poor choice at 14 dKH, IMO.

Water changes can work, but if the salt mix has 10-12 dKH, as many do, the effect will be minimal even with a large change. Even using a 7 dKH mix, a 30% change will only drop alkalinity to 12 dKH. Nevertheless, that is an OK plan.

Waiting for corals and such to use the alkalinity is a good plan, assuming there is reasonable demand in the tank to take it down in a few days. If the demand is very low, it may take a lot longer.

This has more:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

Sound · 10/31/2009, 04:43 PM

Ok, how wold you say is the load with hairy mushrooms, a clam, about ten colonies of zoanthids 10-20 polyps? How long would you estimate it to take?

Yeah, I've done a few water changes for nitrates but it doesn't help so much.

Randy Holmes-Farley · 10/31/2009, 04:46 PM

Of those, only the clam is using alkalinity. If coralline is not growing strongly, which also use alkalinity, it may take a while for it to drop.

What salt mix are you using?

Sound · 10/31/2009, 11:27 PM

Coralline is only growing on the back of the tank. What else would use alkalinity? is there a sponge or something that can lower alk?

I use instant ocean salt.

Randy Holmes-Farley · 11/01/2009, 06:57 AM

I'd just do nothing if it were me in this situation with your tank. Unless you think something is visibly suffering, the cures may cause more harm than the problem does.

IO water changes will not drop alkalinity much since it is pretty high to start with.

There is no sponge for alkalinity. Some products have an effect similar to mechanisms I posted above (like adding soluble lanthanum or iron), but I wouldn't recommend them here.

Henry Bowman · 11/01/2009, 08:56 AM

^^^^

Sound.....Randy may not say it here but.

He is one of the "Sage Advisors" when it comes to reef chemistry. Re-read what he has posted and follow his advice. He's probably forgotten more information than most of the rest of us try to retain regarding reef chemistry.

Randy Holmes-Farley · 11/01/2009, 11:12 AM

Thanks, Henry.

10/31/2009, 11:05 AM	#1
Sound Registered Member Join Date: Jul 2008 Posts: 123	Lowering Alkalinity Hey Guys, My parameters are as follows: PH 8.2 Am 0 Nitrite 0 Nitrates 50ppm (high I know) Calcium 440 Alkalinity 14dkh How do I lower my Alk? It seems like this is the most complicated parameter to adjust and everyone's opinion is different. Things range from massive water changes to doing absolutely nothing and wait for it to go down? Is 14 dkh that bad, or are my nitrates more somehting to worry about?

10/31/2009, 11:56 AM	#2
jenjen Registered Member Join Date: Apr 2008 Location: Langley BC, Canada Posts: 1,710	Here's an article on alkalinity that may be helpful: http://www.wetwebmedia.com/alkalinity.htm I wouldn't worry too much about trying to lower it just yet. I'd be more inclined to get all your other parameters in check, and confirm that your reading is correct for alk before you do anything to try and adjust it. __________________ "Challenges forge the greatness in you" Current Tank Info: 180gal softy reef (Apr '09)

10/31/2009, 01:51 PM	#4
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	How do I lower my Alk? It seems like this is the most complicated parameter to adjust and everyone's opinion is different. The ways to lower alkalinity are not opinion, but which one you choose will possibly be so. Direct acid addition, using muriatic acid/hydrochloric acid or sulfuric acid works perfectly and instantly, but is almost certainly too risky for an existing reef tank at 14 dKH, so I'd avoid that one. Adding so much calcium as to drive down alkalinity by precipitating calcium carbonate will drive calcium very high and will coat pumps and such with calcium carbonate, so that's a poor choice at 14 dKH, IMO. Water changes can work, but if the salt mix has 10-12 dKH, as many do, the effect will be minimal even with a large change. Even using a 7 dKH mix, a 30% change will only drop alkalinity to 12 dKH. Nevertheless, that is an OK plan. Waiting for corals and such to use the alkalinity is a good plan, assuming there is reasonable demand in the tank to take it down in a few days. If the demand is very low, it may take a lot longer. This has more: Solving Calcium and Alkalinity Problems http://www.advancedaquarist.com/issues/nov2002/chem.htm __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

10/31/2009, 04:46 PM	#6
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	Of those, only the clam is using alkalinity. If coralline is not growing strongly, which also use alkalinity, it may take a while for it to drop. What salt mix are you using? __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

11/01/2009, 06:57 AM	#8
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	I'd just do nothing if it were me in this situation with your tank. Unless you think something is visibly suffering, the cures may cause more harm than the problem does. IO water changes will not drop alkalinity much since it is pretty high to start with. There is no sponge for alkalinity. Some products have an effect similar to mechanisms I posted above (like adding soluble lanthanum or iron), but I wouldn't recommend them here. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

10/31/2009, 11:58 AM	#3
rbnice1 Moved On Join Date: May 2008 Location: Cedar Hill Posts: 3,905	Depends on whats in the tank. If it is a sps tank I would say nitrates are your worst problem. Do water changes to bring your nitrates down and it will bring your alk down as well.

10/31/2009, 04:43 PM	#5
Sound Registered Member Join Date: Jul 2008 Posts: 123	Ok, how wold you say is the load with hairy mushrooms, a clam, about ten colonies of zoanthids 10-20 polyps? How long would you estimate it to take? Yeah, I've done a few water changes for nitrates but it doesn't help so much.

10/31/2009, 11:27 PM	#7
Sound Registered Member Join Date: Jul 2008 Posts: 123	Coralline is only growing on the back of the tank. What else would use alkalinity? is there a sponge or something that can lower alk? I use instant ocean salt.

11/01/2009, 08:56 AM	#9
Henry Bowman Reefing since '87 Join Date: Jul 2006 Location: Allegheny Mountains of VA Posts: 2,162	^^^^ Sound.....Randy may not say it here but. He is one of the "Sage Advisors" when it comes to reef chemistry. Re-read what he has posted and follow his advice. He's probably forgotten more information than most of the rest of us try to retain regarding reef chemistry. __________________ Have a good'un Current Tank Info: 90 gl SPS dominant / upgrade in the works

11/01/2009, 11:12 AM	#10
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	Thanks, Henry. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef