Should I adjust Alkalinity?

[NoLobster]

Hey All, I have a 2.5 month old 20 gallon IM Nuvo AIO. You can see more about the build in my build thread: https://www.reef2reef.com/threads/no-lobsters-allowed-20-gal-reef.653171/

I'm using Instant Ocean Reef Crystals and have been testing my Calcium, Alk, and Mg regularly the past few weeks to get a handle on the tank parameters.

Here are my findings over the past 14 day period:

Ph: (monitored by Apex) fluctuates between 7.76 and 8.1 at night and day respectively.

Calcium: 455 ppm average (Salifert test kit)

Alkalinity: 7.3 dKH (Hanna Checker)

Mg: 1230 ppm Avg (Salifert Mg)

Nitrates: 1 ppm (Salifert)

Salinity: 1.026 SG

Phospates: Unsure, I only have the API test kit and it isn't low enough resolution.

Any suggestions based on these parameters? There seems to be no drop in Alkalinity week over week, a slight drop ~10 ppm in calcium, and a slight drop in Mg (~50 ppm). I don't believe my corals are using much and there isn't any coralline algae growth within the tank. I only have one SPS (A small piece of Monti cap) that hasn't grown much over the past 3 months, but isn't bleaching.

Should I try to increase my alk with dosing or just leave everything since it is stable and everyone looks relatively happy?

Bonus Elegance photo for reading:

 

[Tuan’s Reef]

I’m surprised you are only getting 7.3 Alk using Reef Crystals and with little corals you have. I bought a bag once and I was getting 13 dkh on fresh mixed batch. You will fare better with weekly water changes for now.

 

[SliceGolfer]

Looking good! You’re only 2 months in so I would keep everything where it is and ride it out for a while. Once you get some coralline algae going you’ll see a dip in Alk. Water changes should suffice until you see a jump in consumption. You might raise your Mag to 1300-1350, that would be my only suggestion.

I have the same tank and have found great stability in making small changes and testing a week later. For example, my Alk was 7.6 and I kept Alk dose the same. A week later Alk measured 7.1 so I just increased my dose 1 ml extra a day. I‘ll check again this Saturday and see if another adjustment is warranted. Managing my tank slow and steady like this has really paid off in the last two months. Hoping you find a similar rhythm.

Good luck going forward!

 

[jurgenph]

those numbers seem low for reef crystals mixed at 1.026SG.

either your refractometer needs calibrating, or your test results are off.

something doesn't seem right.

J.

 

[Sailfinguy21]

Reef crystals usually gives me like 13 dkh but thats with a new batch or a huge water change... then after 4 days it drops down to like 8 lol... my tank sucks up calcium and alk like mad.

Also higher calcium will push the alk down i would try to maintain 7-8 dkh but lower the calcium to like 420 and i would get the magnesium to 1350-1400

I keep my tank at like 8 dkh. 420 calcium and 1350-1400 mag.

Before i tested for magnesium i noticed two of my acroporas dying... then i had it checked and it qas 1100.. So you being at 1200 is (getting) there.

When was the last time you did a water change ? For a 20g tank.. id probly be doing weekly to biweekky 50% water changes.. but thats just me.

In my 135g tank i do 1/3 of a tank water change every maybe 3 weeks.. So probly 40 gallons or so ? Give or take. Not because i have nitrate or whatever issues but just to replnish lost elements or minerals i cant test for

 

[coralkurd]

I just bought a bucket of reef crystals and I am getting the same alk. Using Hanna checker and getting 7.2-7.3. Even tested my first batch of saltwater made before adding to tank and it was the same. I have been contemplating dosing also but I only have like 3 corals. And not a lot of coraline growth. I got some coraline growth but lasted like a few days. It was also red.

 

[C. Eymann]

OP, next time you do a w/c do a Alk check on the fresh mixed up batch of salt, also are you using a bucket of salt ? reason I am asking, not sure if it's a wives tale or not, but theoretically settling durning shipping can sometimes cause the buffers they use with salt mixes settle more to the bottom, I always shake buckets of salt before using?
Again though, could be debunked by now.

 

[Sailfinguy21]

I just bought a bucket of reef crystals and I am getting the same alk. Using Hanna checker and getting 7.2-7.3. Even tested my first batch of saltwater made before adding to tank and it was the same. I have been contemplating dosing also but I only have like 3 corals. And not a lot of coraline growth. I got some coraline growth but lasted like a few days. It was also red.

You might be seeing cyano not coraline. Specially if it was red.

Did you mix thr bucket ? Turn the bucket uoside down.. roll it around tilt it all over mix it really good. Sometimes itll settle.

I find it hard to believe reef crystals is 7.2. Just seems 2x lower then what it normally has.

If you have only 3 corals i wouldnt bother dosing specially if they arent acroporas or anything like that.. but 7 is on the very low end

 

[NoLobster]

those numbers seem low for reef crystals mixed at 1.026SG.

either your refractometer needs calibrating, or your test results are off.

something doesn't seem right.

J.

I just recalibrated the refractometer and it was still spot on from the previous calibration so I think the Salinity reading is ok. I also checked with a hydrometer and it agreed.

I tested Alk with a Hanna Checker and then also used the API KH kit. I know it isn't perfect but I got somewhere in the 7-8 range with that kit so I think it may be a correct reading from the Hanna Checker.

 

[NoLobster]

Reef crystals usually gives me like 13 dkh but thats with a new batch or a huge water change... then after 4 days it drops down to like 8 lol... my tank sucks up calcium and alk like mad.

Also higher calcium will push the alk down i would try to maintain 7-8 dkh but lower the calcium to like 420 and i would get the magnesium to 1350-1400

I keep my tank at like 8 dkh. 420 calcium and 1350-1400 mag.

Before i tested for magnesium i noticed two of my acroporas dying... then i had it checked and it qas 1100.. So you being at 1200 is (getting) there.

When was the last time you did a water change ? For a 20g tank.. id probly be doing weekly to biweekky 50% water changes.. but thats just me.

In my 135g tank i do 1/3 of a tank water change every maybe 3 weeks.. So probly 40 gallons or so ? Give or take. Not because i have nitrate or whatever issues but just to replnish lost elements or minerals i cant test for

My Magnesium has been dropping which I find a bit odd. It started at around 1400 and is now down to 1200 over a 14 day period. I only have 1 test kit for Mg though and I was just learning how it is used so I may have messed up the first test.

Calcium and Alk have stayed pretty steady.

I do a weekly 20% wc. I think this is a fair wc amount for a 20 gallon. If I do a larger change, it really has the ability to affect my parameters a large amount in a very short time which I don't think is great for stability and the health of the inhabitants. My parameters don't seem to be at a dangerous level for anything or dropping super precipitously so that is why I have kept the changes smaller. I may need to up it a bit to 25 or 30 though to see how that affects my parameters.

 

[NoLobster]

You might be seeing cyano not coraline. Specially if it was red.

Did you mix thr bucket ? Turn the bucket uoside down.. roll it around tilt it all over mix it really good. Sometimes itll settle.

I find it hard to believe reef crystals is 7.2. Just seems 2x lower then what it normally has.

If you have only 3 corals i wouldnt bother dosing specially if they arent acroporas or anything like that.. but 7 is on the very low end

I saw the brs video on reef crystals so I did try to mix it some. It's a heavy bucket though xD. It's hard to mix effectively, but I will keep shaking it around every time I do a wc.

 

[NoLobster]

OP, next time you do a w/c do a Alk check on the fresh mixed up batch of salt, also are you using a bucket of salt ? reason I am asking, not sure if it's a wives tale or not, but theoretically settling durning shipping can sometimes cause the buffers they use with salt mixes settle more to the bottom, I always shake buckets of salt before using?
Again though, could be debunked by now.

You're right, in Reef Crystals especially there is the possibility of the top and bottom having very different makeups. BRS did a video on Youtube about the parameters for different buckets of salt using the top and bottom. Mine may just be in the low alk section

Good call on the testing the fresh saltwater before adding it to the tank. I will do that next water change.

 

[C. Eymann]

You're right, in Reef Crystals especially there is the possibility of the top and bottom having very different makeups. BRS did a video on Youtube about the parameters for different buckets of salt using the top and bottom. Mine may just be in the low alk section

Good call on the testing the fresh saltwater before adding it to the tank. I will do that next water change.

there was a hot debate about that a long time ago on my local reef forum, I wasnt sure if it had be debunked or not.