What is using up my dKh???

[EvanSPS6]

Ok so I set up a 20g nano at the beginning of July and started adding CUC and fish by the end of August. I also added a zoa frag during this time.

 

I never test for alkalinity, calcium or mag, I use red sea salt (blue bucket) and assumed my values would be around there as there is not really any major coral in my tank that would use it up. Recently I added an acan frag, it was at this point that I decided to test my alkalinity and it turned out to be 6dKh. I tested my water change mix and it was 8dKh just as labelled on the bucket.

Any idea how my alk could have dropped so low?

Other parameters are:

pH: 8.0

Nitrate: 1-5ppm

Phosphate: 0.02ppm

Calcium: 390

Mag: 1390

 

I'd also like to add that I stick to about 15-20% water changes every week

[Gravity]

What is the salinity of the mixed water and of the tank? What are you using to check salinity? I use Red Sea blue bucket and it mixes to:

salinity - 1.026  (35ppt)

Alk - 8.0 dkh

Ca - 450

Mag - 1500

 

 

[PowderedToastMan]

If you have coralline algae it will use Alk.

[SliceGolfer]

I would chalk it up to new tank blues. I looked back at my log when my 20 was set up. I use RSBB salt as well, mixed to 35ppt. I see my tank went from 8dkh to 6.5dkh after cycle, then hovered at 7dkh for a bit. I would try water changes over the next couple weeks, but really you’re going to need some 2part solution if you want to raise it to your liking. BRS 2part works really well and is inexpensive. Lots of YouTube how to dose 2part like BRS or ESV Bionic. With zoas and an acan, you should be ok raising the DKH by .5 a day.

[Clown79]

I use RS blue bucket

 

With 1.026 my salt mixes at 8.2 dkh.

 

Did you go online and check the batch number for its dkh, every bucket has a batch number and you can get that batches actual parameters.

 

 

[SliceGolfer]

I’ve also read from some folks that CaribSea life rock causes some precipitation which might account for your drop over the two month period.

 

(Note: OP isn’t questioning levels at mix but the drop over two months in a new system)

[EvanSPS6]

7 hours ago, Gravity said:

What is the salinity of the mixed water and of the tank? What are you using to check salinity? I use Red Sea blue bucket and it mixes to:

salinity - 1.026  (35ppt)

Alk - 8.0 dkh

Ca - 450

Mag - 1500

 

 

I mix to 35ppt and tested it at 8.0dkh

[EvanSPS6]

6 hours ago, SliceGolfer said:

I would chalk it up to new tank blues. I looked back at my log when my 20 was set up. I use RSBB salt as well, mixed to 35ppt. I see my tank went from 8dkh to 6.5dkh after cycle, then hovered at 7dkh for a bit. I would try water changes over the next couple weeks, but really you’re going to need some 2part solution if you want to raise it to your liking. BRS 2part works really well and is inexpensive. Lots of YouTube how to dose 2part like BRS or ESV Bionic. With zoas and an acan, you should be ok raising the DKH by .5 a day.

My two corals seem happy I guess. My zoas have grown two new polyps since I got them. Hopefully it is just new tanks blues, I will continue with water changes and testing for another few weeks and then look into dosing. It's a shame though, I was hoping not to start dosing until I filled out my tank a little more.

[EvanSPS6]

6 hours ago, Clown79 said:

I use RS blue bucket

 

With 1.026 my salt mixes at 8.2 dkh.

 

Did you go online and check the batch number for its dkh, every bucket has a batch number and you can get that batches actual parameters.

 

 

I actually tested the fresh saltwater mix before the water change and it came up at 8dkh

[SliceGolfer]

You likely won’t be dose “ing” versus one or two doses. Water changes will get dkh back on track. If you want it to happen sooner then you will need to supplement with 2part. I suspect once you have dkh where you want it then it won’t fluctuate much at all. Same with calc and mag, get them to 440ppm calc and 1440ppm mag as an example and they’ll likely stabilize until you add more corals.

[MrObscura]

Blue bucket mixed to 1.026 comes in at 8.4dkh for me. At least my current batch.

 

Anyway tanks can do weird things. Mine went from having stable alk for months to suddenly jumping up 2+ points for no apperant reason despite no dosing. Recently I just did a number of successive waterchanges to get it back were I want it and its stable again.

[billygoat]

4 hours ago, MrObscura said:

Blue bucket mixed to 1.026 comes in at 8.4dkh for me. At least my current batch.

 

Anyway tanks can do weird things. Mine went from having stable alk for months to suddenly jumping up 2+ points for no apperant reason despite no dosing. Recently I just did a number of successive waterchanges to get it back were I want it and its stable again.

My system also consumes a steady amount of Alk solution (enough to warrant daily dosing) but almost no Ca. Why? I have no idea. 🤷‍♂️😂 Very few stony corals, just a lot of softies and coralline algae. I suspect that some microorganisms that have an interest in carbonate ions but not in calcium ions may also be at work.

[EvanSPS6]

Thanks for all the replies everyone! Gonna wait it out a little longer and not add anymore corals until the tank balances out or until I dose it back up.

[mcarroll]

On 10/20/2019 at 10:22 PM, billygoat said:

suspect that some microorganisms that have an interest in carbonate ions but not in calcium ions may also be at work.

This.

 

Exactly the reason Instant Ocean and all the other "basic" salts that aren't intended for reefs STILL have elevated (reserve) levels of alk.  Lots of bio processes use carbonates I guess...just not as quickly as a full crop stony corals will.

[EvanSPS6]

Ok so I dosed baking soda slowly to bring it back up to 8dkh. After a week I tested again to see that my dkh is at 7dkh, is this too significant of a drop for only a small frogspawn colony, a small acan and zoa frag?

[kimberbee]

On 10/20/2019 at 8:20 AM, Gravity said:

What is the salinity of the mixed water and of the tank? What are you using to check salinity? I use Red Sea blue bucket and it mixes to:

salinity - 1.026  (35ppt)

Alk - 8.0 dkh

Ca - 450

Mag - 1500

That seems decently far off from the advertised parameters for blue bucket. How often do you check your fresh mixed water? I'm looking for a new salt because I'm not happy with the elevated alk in coral pro, I skipped over blue bucket cause of their advertised levels,  but what you posted above is very close to what I'm trying to find. 

[Tamberav]

It could be coralline algae.

 

However it is also worth noting that Nitrate effects Alk and in a young tank, Nitrate is probably not stabilized yet. If Nitrate is being consumed, alk will rise. In one of my tanks, it uses up so much Nitrate, that when I started dosing NO3, my alk increased without adding 2part. Similarly if your Nitrate is increasing, alk will drop. 

 

Young tanks do wacky things as there are many biological processes going on we can not see or test for. Keep on your toes.

 

 

[frahny]

Truth👆, honestly I wouldn't worry about what your DKH is anyways unless corals are unhappy. Your tank is going to mature and settle where it wants, once you add corals slowly you can then start your dosing phases to keep them consistent. Many people have experiences that differ, one persons tank is going to thrive at 7 DKH others 8.5, the key is consistency. Hell, I think I just read somewhere that Jake Adams from Reefbuilders had his nano at 5.5 or 6 DKH and everything was doing great. Just be careful not to chase numbers, but chase stability.

[I'm Batman]

I’m having this same issue now in my 6 gal. JBJ and for some reason I can’t get it through my head how alk works. 
 

IO Reaf Crystals mixes to 10dkh. Put it in the tank and it comes out around 7.5-8dkh.

 

Next morning I’m down to 6dkh. Been dosing Polyplabs One and I’m hovering around 6.5dkh but am I chasing dkh or what?

 

[frahny]

16 hours ago, I'm Batman said:

I’m having this same issue now in my 6 gal. JBJ and for some reason I can’t get it through my head how alk works. 
 

IO Reaf Crystals mixes to 10dkh. Put it in the tank and it comes out around 7.5-8dkh.

 

Next morning I’m down to 6dkh. Been dosing Polyplabs One and I’m hovering around 6.5dkh but am I chasing dkh or what?

 

what test kit are you using?

 

 

[I'm Batman]

Hanna Alk checker with brand new reagent 

[Gravity]

On 12/3/2019 at 6:37 PM, I'm Batman said:

I’m having this same issue now in my 6 gal. JBJ and for some reason I can’t get it through my head how alk works. 
 

IO Reaf Crystals mixes to 10dkh. Put it in the tank and it comes out around 7.5-8dkh.

 

Next morning I’m down to 6dkh. Been dosing Polyplabs One and I’m hovering around 6.5dkh but am I chasing dkh or what?

 

Here is a great video on water chemistry. Also make sure your salinity is correct, check with a calibrated refractometer. Follow mixing directions closely IO Reef Crystal and other elevated alkalinity salts are also more likely to precipitate out. 

 

[I'm Batman]

Salinity a little high at 37ppt, recalibrated my atc refractometer. Calcium at 600 (Salifert) Magnesium at 1600 (Salifert). Found my cause in the video. Sounds like when mag is high and calc is up, dkh teeters. He doesn’t cover how to fix that although he ends with 30 seconds on carbon dosing. 
 

How many people are having issues because their salinity measurement device is out of caliber which causes too much in a high calc, mag salt? 
 

I’ll lower the salinity and see what happenes next! 
 

Anybody else chasing low dkh?

[I'm Batman]

If your alk is low according to that video your mag and calcium should be sky high. 
 

 

[mcarroll]

That's no way to learn about alkalinity (tho a fine way to pique your interests)....instead look for articles on reefkeeping.com and advancedaquarist.com about alkalinity.  Read them all.  😁