Low alkalinity suggestion

[Jakepen]

Hey guys, I have a 30 gallon, a little over a month old, have a few lps coral in there. I am using HW Reefer salt, mixing at 1.026, just did a ten gallon change yesterday. Tested the fresh mixed water, read 9.2 dkh. Changed the water yesterday, tested it today and it's at 7.5dkh. I don't think my tank is usuing up alk that quickly, is it? What should I do to raise it, i was thinking limewater, or maybe Red Sea coral pro, mix some in with my current salt? Any ideas?

 

[Servillius]

Don't do anything. See what happens at the next water change. A few LPS are not consuming a lot of carbonate.

 

[Kershaw]

Just keep testing. 7.5 is fine. Test every day for a week to see if your coral is consuming it.

 

[Jakepen]

I'll test daily this week and see what if does. I'm using the Hanna alk checker.

 

[Kershaw]

Get another test kit to confirm. Api kh test kit are good and cheaper they have always been with in .5 of every other test I have tried

 

[Servillius]

I'll test daily this week and see what if does. I'm using the Hanna alk checker.

Testing daily will only cause you stress and upset. Test once or twice a week.

 

[watchguy123]

Testing daily will only cause you stress and upset. Test once or twice a week.

I test typically twice a week at least. Sometimes daily and I expect consistency. I use Hanna checker which is as reliable and accurate as other test kits which is ok.

 

[Servillius]

I test typically twice a week at least. Sometimes daily and I expect consistency. I use Hanna checker which is as reliable and accurate as other test kits which is ok.

I do occasionally check alkalinity daily, so you're not alone. That said it is important to realize while I have found the Hanna checker to be more accurate and more precise than any other hobby kit, it is not perfect. Hanna reports +/-5ppm +/-5% of reading. That means at 150ppm the error can be as much as 12.5ppm in either direction giving a range of outcomes from 137.5 to 162.5ppm (more accurately they probably mean 95 or 99% of the results are in this range). While I don't typically experience that range of results, I use a lab pipettor and keep my machine and glassware meticulously clean.

 

[Kershaw]

I like he Hanna and am waiting for there new alk one. But finger prints on bottle can throw them off. I have phosphate one I love it. But every now and then I check it agenst another test kit

 

[Jakepen]

Well I figure testing daily until I know what my tank is doing is a good idea. Test all my parameters every Friday, well the main ones. For now though I'm going to test alk daily, to see if I can monitor the consumption.

 

[Servillius]

Well I figure testing daily until I know what my tank is doing is a good idea. Test all my parameters every Friday, well the main ones. For now though I'm going to test alk daily, to see if I can monitor the consumption.

Whatever works best for you and all that...

What I'm getting at though is monitoring daily actually makes it harder to monitor consumption.

Imagine I get these results - M 150, T 135, W 155, Th 145.

Did your tank use 15ppm between Monday and Tuesday? Then it gained 20ppm on Wednesday? 20ppm is a lot right?

The answer is not necessarily though. All those results are consistent with an alkalinity of 150 or so. Your alkalinity didn't bounce around like a ping pong. It stayed roughly the same. If you were using another test kit it would have stayed at an 8dkh. Now you're sitting there with a book on statistics looking up the definition of standard deviations and wondering if the 20ppm drop is significant when in fact if you look at the end points you'd probably conclude after 4 days it hadn't changed enough to be of note.

Even if you're flawless the test isn't. I think I can get within a band 5ppm wide pretty consistently. That sounds good, right? What if I get 140, 145, 150, 155? 5 a day, right? It could just as easily be 1.25 a day. Estimating your consumption at 4x the actual is going to result in a lot of bad guess even with great testing.

Wait a few days. If you see a change of 30ppm or more then make an adjustment. If not, wait and keep checking occasionally.

 

[Lenair Stevens]

I'm curious too. Is there an ideal alkalinity. I read that 8-12 dKh is fine but that seems like a wide range. Some of my LPS don't seem to open all the way. Could an 8.5 alkalinity contribute to that? Would it be better at 9.5? My calcium and mag are at 420 and 1340 respectively.
Hope it is ok to butt in.

 

[Randy Holmes-Farley Verified Community Expert]

Corals will grow slower in lower alk, but won't really be stressed unkless the alk drops below 7.

FWIW, coralline algae alone can use 2-3 dKH of alk a day in some reef tanks, so it is not just hard corals.

There are many good ways to boost alk, and in a pinch, baking soda is as good as anything else.

I compare different methods here:

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION
https://www.reef2reef.com/blog/the-many-methods-for-supplementing-calcium-and-alkalinity

 

[Kershaw]

Corals will grow slower in lower alk, but won't really be stressed unkless the alk drops below 7.

FWIW, coralline algae alone can use 2-3 dKH of alk a day in some reef tanks, so it is not just hard corals.

There are many good ways to boost alk, and in a pinch, baking soda is as good as anything else.

I compare different methods here:

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION
https://www.reef2reef.com/blog/the-many-methods-for-supplementing-calcium-and-alkalinity

Coraline is my issue. It sucks up a ton of it.

 

[Jakepen]

I'm trying to decide what's best. My alk isn't very high out of the gate, and I've heard limewater only maintains levels, doesn't necessarily raise them? I would like to get my alk levels higher, my calcium and magnesium levels are regularly high, so I'm not concerned, almost don't want to raise them any more. Kalkwaser seems like the easiest route, as I already have a ATO. Two part, seems like a lot more work, more plugs which I don't have room for, and potentially not needed? Will kalkwaser get me where I want?

 

[Randy Holmes-Farley Verified Community Expert]

I'm trying to decide what's best. My alk isn't very high out of the gate, and I've heard limewater only maintains levels, doesn't necessarily raise them? I would like to get my alk levels higher, my calcium and magnesium levels are regularly high, so I'm not concerned, almost don't want to raise them any more. Kalkwaser seems like the easiest route, as I already have a ATO. Two part, seems like a lot more work, more plugs which I don't have room for, and potentially not needed? Will kalkwaser get me where I want?

The limewater comment isn't true. What you cannot do with it is boost calcium substantially because alk will get too high, and you cannot boost alk too much at once because the pH will get too high.

But slow dosing can allow alk and calcium to rise int he ratio if 2.8 dKH per 20 ppm calcium.

FWIW a two part does not require dosing pumps, and if you want, you can put the alk supplement (almost any alk supplement) into the ATO. But I used limewater in mine for more than 20 years.

 

[Jakepen]

The limewater comment isn't true. What you cannot do with it is boost calcium substantially because alk will get too high, and you cannot boost alk too much at once because the pH will get too high.

But slow dosing can allow alk and calcium to rise int he ratio if 2.8 dKH per 20 ppm calcium.

FWIW a two part does not require dosing pumps, and if you want, you can put the alk supplement (almost any alk supplement) into the ATO. But I used limewater in mine for more than 20 years.

That's what u think I'm going to do. Seems the most simple just to dose my ATO with supplements. I think I'll try limewater, going to read your write up on it pretty carefully. Thanks so much randy. Also, I just implemented a co2 scrubber on my skimmer, brought my ph to 8.2. Will using limewater raise it up to much? Should I consider taking the scrubber off?

 

[Anthony123]

I am having low ph 7.7-7.8 and low alkalinity 6-7 for awhile now. I have been doing small water changes to try and bring it up but doesn't seem to help. It's a 30 gallon tank with minimal corals at the moment. Supply fresh outside air to skimmer and have a small refugium.

 

[Kershaw]

Do y

I am having low ph 7.7-7.8 and low alkalinity 6-7 for awhile now. I have been doing small water changes to try and bring it up but doesn't seem to help. It's a 30 gallon tank with minimal corals at the moment. Supply fresh outside air to skimmer and have a small refugium.

ou have allot of coraline growing?

 

[Kershaw]

I am having low ph 7.7-7.8 and low alkalinity 6-7 for awhile now. I have been doing small water changes to try and bring it up but doesn't seem to help. It's a 30 gallon tank with minimal corals at the moment. Supply fresh outside air to skimmer and have a small refugium.

You may need to start dosing the alk from a two part. What are the rest of your water peramiters