Reef Crystals and My Struggle with Low Alkalinity

RobberyinCSharp1824

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I've been struggling to get a grip on a low alkalinity problem in both my tanks. I've got a 20g reef only tank with a few beginners corals (zoas, acans, etc.) and two SPS corals (purple birdsnest and a green pavona). They all seem fine, the birdsnest is doing well, but my pavona is starting to show some signs of struggle. I've also got a 120g tank that just has a yellow tang and one anthias (plus snails) for now. New members TBD after QT.

The best I've ever been able to keep my reef at for alk is 8.1 - I generally hovered around low 7's, high 6's. I just tested my FOWLR tank and the alk was at 4.47 and my reef was at 5.2!!! I'm using a Hannah Alk Checker to monitor alk in both tanks and check my parameters every Saturday morning. Calcium and Magnesium are rarely an issue for me - pH generally stays around 8.0 with fluctuation between 7.8 - 8.2. When Ca/Mg drops I add some Prime Reef Fusion and I'm good to go.

I started trying to correct these issues by using the Reef Chemistry Calculator and making a concentrated solution of baked baking soda and RODI water that I would slowly titrate into my tanks until they reached the correct alk levels, while monitoring my pH to prevent severe swings while I raised alk. I tried to see if being more religious about water changes would also help stabilize and maintain correct alk levels - I've now comet to discover, in fact, it made the situation WORSE.

I'm currently using Instant Ocean's Reef Crystals. I finally decided to figure out what the heck the baseline was after making RODI water (from city tap water using my AquaFx Barracuda system) and mixing reef crystals in. The water mixed for about 12 hours (excessive, I know. I had lost track of time and forgot about it and went to bed - results are from the AM). The alk results were disappointing to say the least:

Salinity: 1.024
Magnesium: 1380
Calcium: 480
pH: 8.1
Alkalinity: 5.768!?

I always wash my cuvettes with DI water when I am done with them. I also "prime" the cuvette by filling it up with the test water, shaking it up, and dumping it out, prior to filling it with the official test vial. My alk testing solution is probably only one month old and doesn't expire until 2022 or 2024.

Has anyone else had experience with reef crystals and low alkalinity? I've been compensating by adding my baked baking soda to my mix but it's a PITA to wait for the CO2 exchange to bring the pH down to safe levels again. What the heck do I do in the meantime? I'm itching for some new corals for my tank but I don't want to add any inhabitants until this gets straightened out.
 
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RobberyinCSharp1824

RobberyinCSharp1824

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Never had low alk issue with RC..maybe your tester is suspect?

Maybe. One of the things I've always been skeptical about with Hannah is calibration. Unless I missed something in the manual, I suspect the reader gets less accurate over time and needs to be calibrated (as almost all equipment does).

I use RC as well and my alk ends up being 10 after mixing. I mix for 24 hours
Hmmm. Maybe I'm not mixing my salt long enough? @rwreef how long do you mix for?
 

Jen1978

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I really don't think any salt should be mixing that low. My tropic marin pro mixes almost consistently at 7.5 so I just dose a little bit of Soda Ash from Bulk reef supply. If it is mixing that low, then water changes wouldn't help much to bring it up. I would also doubt the tester at this point as I assume you are making sure to have all finger prints off of it. I'm even more puzzled by the fact that cal and mag are ok. With Alk that low, they should be high. Again, leads me to believe something is wrong with the tester somewhere.

In addition, I'd suggest taking a sample to a LFS for a second oponion.
 
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RobberyinCSharp1824

RobberyinCSharp1824

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I really don't think any salt should be mixing that low. My tropic marin pro mixes almost consistently at 7.5 so I just dose a little bit of Soda Ash from Bulk reef supply. If it is mixing that low, then water changes wouldn't help much to bring it up. I would also doubt the tester at this point as I assume you are making sure to have all finger prints off of it. I'm even more puzzled by the fact that cal and mag are ok. With Alk that low, they should be high. Again, leads me to believe something is wrong with the tester somewhere.

In addition, I'd suggest taking a sample to a LFS for a second oponion.

Testing at the LFS is actually a great idea; no idea why I didn't think of that in the first place! I trust my LFS and it's only 10min from my house.

I do wipe my thumbprints prior to testing; sometimes there is a negligible bit of particulate matter floating in the sample, but I wouldn't suspect it would throw readings off so significantly.
 

ScubaFish802

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Are you / Did you mix the dry salt in the bucket before using it to mix with water?
 
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RobberyinCSharp1824

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Are you / Did you mix the dry salt in the bucket before using it to mix with water?

I'm not sure I understand your question. I add dry salt to my RO/DI water which was warmed to ~72F and is actively being circulated by a Hydor Koralia 2450gph powerhead in a 20g Brute container. I follow the instructions on the reef crystals bucket so I get the correct salinity. I generally let it mix for a few hours, and then test the salinity prior to adding it to my tank.

Once it is at the right salinity, I just grab 10mL using a clean pipette and test the sample for alk from that.

I always add freshly made water to my tank and never dose salt directly in, per the instructions, as it can cause burns to habitants.
 

ScubaFish802

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Sorry, I should have clarified more.
I was having issues with Reef Crystals not mixing to what it should as well.

A few members on here stated I should be mixing the dry - salt mix itself before using it to mix with water to make saltwater.

I took the entire RC bucket and dumped it into a new trash bag and mixed the heck out of it before dumping it back into the RC bucket.

I guess the idea is the mix can settle and create pockets, so by mixing the dry salt first you prevent that.

I haven’t had any irregularities with my water since, not sure if that may help your situation
 

SteveMM62Reef

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I buy that same Salt in the 200 gallon boxes. There are Four bags in each box. I throughly mix the salt in the bags before opening. Once the bag is opened, it goes in an old Reef Crystals bucket, with the bag folded over and the lid firmly snapped down. I only mix it with RO/DI also if the water is too cold, I notice that a I get a calcium coating on the Brute Container. I use a small internal Fluval Filter to mix everything up. BTW I do not recommend this Filter, it’s to hard to clean and maintain, and it has no head pressure. Since their are no LFS near me, I purchase Salt at Walmart on line, and get it shipped to the store.
 

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Sorry, I should have clarified more.
I was having issues with Reef Crystals not mixing to what it should as well.

A few members on here stated I should be mixing the dry - salt mix itself before using it to mix with water to make saltwater.

I took the entire RC bucket and dumped it into a new trash bag and mixed the heck out of it before dumping it back into the RC bucket.

I guess the idea is the mix can settle and create pockets, so by mixing the dry salt first you prevent that.

I haven’t had any irregularities with my water since, not sure if that may help your situation
I notice your salinity at 1.024 if you brought it up to 1.026 this would bring alk up also
 

ocboat

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It's probably your alkalinity reagent. I just went through this with Instant Ocean salt mix and thought I had a bad batch when my new salt tested at 5 dkh with my Hanna tester using the same bottle of reagent that I had been using for the last couple of months. I then opened a new bottle of reagent and my mix tested at 9 dkh! I had been trying to raise my tank alkalinity because of these false results and luckily it was only at 10.5.
 

Bluedore

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Sorry, I should have clarified more.
I was having issues with Reef Crystals not mixing to what it should as well.

A few members on here stated I should be mixing the dry - salt mix itself before using it to mix with water to make saltwater.

I took the entire RC bucket and dumped it into a new trash bag and mixed the heck out of it before dumping it back into the RC bucket.

I guess the idea is the mix can settle and create pockets, so by mixing the dry salt first you prevent that.

I haven’t had any irregularities with my water since, not sure if that may help your situation
Plus 1 on this! I also had similar issues with RC, I buy the 200g That comes in 4 bags and some mixes at 12+DKH while some around 6, 7, 8 etc...all over the place.
 

Albertan22

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If you are getting particulate matter/floaties in your test vial from the reagent then your reagent has gone bad and will be reading low. They only last about 6 weeks once opened.
 

rwreef

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Maybe. One of the things I've always been skeptical about with Hannah is calibration. Unless I missed something in the manual, I suspect the reader gets less accurate over time and needs to be calibrated (as almost all equipment does).


Hmmm. Maybe I'm not mixing my salt long enough? @rwreef how long do you mix for?
I mix mine overnight typically. However I've also used it within hours if making it.
 

92Miata

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I had a box of RC that sat around for a couple years. When I opened it up, it would mix up to about 4.5 dKH. Does your bucket have a date on it anywhere?
 
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RobberyinCSharp1824

RobberyinCSharp1824

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Man, this is why I love this forum! You guys are so helpful!

Sorry, I should have clarified more.
I was having issues with Reef Crystals not mixing to what it should as well.

A few members on here stated I should be mixing the dry - salt mix itself before using it to mix with water to make saltwater.

I took the entire RC bucket and dumped it into a new trash bag and mixed the heck out of it before dumping it back into the RC bucket.

I guess the idea is the mix can settle and create pockets, so by mixing the dry salt first you prevent that.

I haven’t had any irregularities with my water since, not sure if that may help your situation

That is very good to know. I wouldn't have thought of that but I guess it makes sense! It's an easy enough fix so I should give it a shot! Thanks!

If you are getting particulate matter/floaties in your test vial from the reagent then your reagent has gone bad and will be reading low. They only last about 6 weeks once opened.
So the PM can also be seen when I add the water from the Brute bucket; I suspect it's a very small amount of buildup of calcium or something else from adding my soda ash.

It's probably your alkalinity reagent. I just went through this with Instant Ocean salt mix and thought I had a bad batch when my new salt tested at 5 dkh with my Hanna tester using the same bottle of reagent that I had been using for the last couple of months. I then opened a new bottle of reagent and my mix tested at 9 dkh! I had been trying to raise my tank alkalinity because of these false results and luckily it was only at 10.5.

That's so frustrating, but I wouldn't be surprised at ALL. I also have a phosphate tester; the latest batch of reagents ONLY reads 0 and has been for the last several weeks. That sounds like BS to me. Maaaaayyyyyyybe in the 20g reef because there is so little food/waste being produced but my 120 absolutely should have phosphate readings. For a $50 checker and a $15 reagent, they really need to get their act together! QC control is important!!!!

Plus 1 on this! I also had similar issues with RC, I buy the 200g That comes in 4 bags and some mixes at 12+DKH while some around 6, 7, 8 etc...all over the place.

That was something I was wondering about as well. I buy the large buckets that make 200g or so of mix, since I can re-use the buckets to perform water changes and such. I really wish these manufacturer's would get their QC control straightened out. :(
 

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