Instant Ocean Alkalinity Variance

[Reef AquaCult]

I have been using IO (regular, NOT Reef Crystals) for the past 6 months. My alkalinity was rock solid at 8.6 using Hanna Alk checker testing every 2 weeks for several months. I keep my new saltwater in a 90 gallon food grade polyethylene tank that was purchased new. I mix new saltwater in 45-50 gallon increments (when my tank gets to about half full) and simply pour on of the 50 gallon bags of IO into and mix to 1.025 SG for 6-8 hours. After the last bag was added the alkalinity in the tank is now 7.2 per the Hanna checker with same SG of 1.025. The Hanna reagent is not expired and I even opened a new bottle of reagent (both old and new read the same within 0.2). I tested the stagnant water (no mixing x several days) and after a thorough mixing with pump and obtained the same measurements. I would like to know some of your alkalinity values with mixing new saltwater with standard Instant Ocean and what type of variability in readings you would typically expect. I'm well aware IO is the budget salt but I would expect the alkalinity to be more consistent than the readings I'm getting. Thank you for any input!

 

[SeaDweller]

IME with IO it usually ran high, not low. It was 9.0-9.6+ on multiple boxes of standard IO.

 

[homer1475]

I've used IO exclusively for about 4 years now, always mixes up to anywhere between 9 and 10DKH.

 

[Reef AquaCult]

Interesting, thank you for the responses. I wonder whats going on in my case. I’m dumping the entire contents of each bag in so layering / stratification should not be happening. Corals don’t seem to be affected right now so I don’t plan on changing anything urgently but will definitely keep monitoring it.

 

[BeejReef]

Not for nuthin, but dumping in the whole bag could be an issue. I say "could" bc I don't definitively know. Still, I think best practice is to add it somewhat slowly. I only add as fast as I can with a 1/2 cup, giving each one a good jiggle.

Are you saying your salt mix bin is lower in alkalinity, or your DT has a lower alk than ususal?

 

[Bryknicks]

Interesting, thank you for the responses. I wonder whats going on in my case. I’m dumping the entire contents of each bag in so layering / stratification should not be happening. Corals don’t seem to be affected right now so I don’t plan on changing anything urgently but will definitely keep monitoring it.

I just had a new bag of R.C. have very low ALK in comparison to all my other batches. Wonder if anyone else had this issue

 

[DivingTheWorld]

I use regular instant ocean, but always reduce the Alk to 7.5. Here is what my batches have mixed up to at 1.0264 before I reduced the Alk:

06/18 - 10.584
07/25 - 9.8
08/21 - 8.904
09/11 - 8.232
10/09 - 9.688

 

[Reef AquaCult]

Not for nuthin, but dumping in the whole bag could be an issue. I say "could" bc I don't definitively know. Still, I think best practice is to add it somewhat slowly. I only add as fast as I can with a 1/2 cup, giving each one a good jiggle.

Are you saying your salt mix bin is lower in alkalinity, or your DT has a lower alk than ususal?

Both the new saltwater and now display tank (setup for AWC) have low alk now. I do shake the salt in to ensure even mixture but will be sure to take it slower next time.

 

[Reef AquaCult]

I use regular instant ocean, but always reduce the Alk to 7.5. Here is what my batches have mixed up to at 1.0264 before I reduced the Alk:

06/18 - 10.584
07/25 - 9.8
08/21 - 8.904
09/11 - 8.232
10/09 - 9.688

Thank you. Those are what I would expect. Not low 7’s

 

[Donny41]

I haven't had an alk issue with my current I.O box but it has been mixing out with elevated magnesium compared to old batches. Sounds like a few bad boxes might have gone out

 

[SeaDweller]

Interesting, thank you for the responses. I wonder whats going on in my case. I’m dumping the entire contents of each bag in so layering / stratification should not be happening. Corals don’t seem to be affected right now so I don’t plan on changing anything urgently but will definitely keep monitoring it.

Honestly, I wouldn't be complaining about IO if the alk mixed up liked that! I usually have to drop the alk with some product to get it into that 7.x range

 

[Randy Holmes-Farley]

It may not be in play here, but the alk in salt mixes can decline over time as calcium carbonate precipitates in the container. This is much more prone to happen in raw salt water than in the aquarium where a variety of chemicals serve to reduce the rate of precipitation. How much it happens can vary with how you mix it. It’s why you do not add water to salt, but salt to water.

 

[Reef AquaCult]

It may not be in play here, but the alk in salt mixes can decline over time as calcium carbonate precipitates in the container. This is much more prone to happen in raw salt water than in the aquarium where a variety of chemicals serve to reduce the rate of precipitation. How much it happens can vary with how you mix it. It’s why you do not add water to salt, but salt to water.

Thank you for your feedback. Will continue to monitor and update.

 

[Ross Petersen]

It may not be in play here, but the alk in salt mixes can decline over time as calcium carbonate precipitates in the container. This is much more prone to happen in raw salt water than in the aquarium where a variety of chemicals serve to reduce the rate of precipitation. How much it happens can vary with how you mix it. It’s why you do not add water to salt, but salt to water.

Hey Randy - old thread here. Does one have to worry about alk swings for new corals? I have a coral QT tank and my new Instant Ocean water is coming out around 10 dKH (via Hanna) whereas the corals I am receiving (beginner SPS and euphyillia, including torches) are housed in 8-8.5 dKH water I'm informed.

I'd like to keep my dKH in my display tank at around 8.5-9.0.

Probably should have avoided regular Instant Ocean - wasn't aware the alk comes out so high. BRS did a video affirming the high alk on mixing. Whoops.

 

[Randy Holmes-Farley]

The swing will only be an issue if you do largish water changes.

A 10% change with 11 dKH water on a 9 dKH tank only boosts alk from 9.0 to 9.2 dKH, which is fine.

 

[stanlalee]

Not Randy but I'm not that consistent with alk (not because of salt. I do 20% water changes weekly, percentage wise that is self explanatory why it's not significant). I hand dose daily sometimes 8 hours off from the previous day (I work, fall asleep etc) but I test alk via Hanna meter nearly everyday and vary between 9-10 routinely. LPS and soft corals could care less for sure. I only have 4 acropora frags and they don't seem to particularly care. I have 2 monti caps that do terrible and one that does ok (the one I've had the longest) which may or may not be attributed to alk swings. With that being said this isn't my first rodeo and I've had a reef with a bunch of sps, lps and zoas which I hand dosed, only tested once a week and used API dKH test which have no resolution (1dkh) and EVERYTHING did well long term so I feel like plus minutes 1dKH swings are overstated when it comes to coral health.

 

[Ross Petersen]

Thanks Randy.

As corals are going from 8 dKH at the LFS to my coral QT at about 10 dKH, I assume then that this will be a problem, even with a longer drip acclimation?

If so, how do you recommend I lower the dKH of my Instant Ocean supply water?

Thanks

The swing will only be an issue if you do largish water changes.

A 10% change with 11 dKH water on a 9 dKH tank only boosts alk from 9.0 to 9.2 dKH, which is fine.

 

[Ross Petersen]

That’s my gut instinct as well.

Now with a 2-3 dKH swing, that is likely more of an issue for sensitive torches and SPS I suspect?

Instant Ocean salt comes out to 10-11 dKH and most suppliers run at 8-9 dKH. Is this a major problem for those running coral QT tanks with Instant Ocean water and newly purchased corals?

I’m leaning towards changing salts if this could be the reason I just lost a gold torch.

Not Randy but I'm not that consistent with alk (not because of salt. I do 20% water changes weekly, percentage wise that is self explanatory why it's not significant). I hand dose daily sometimes 8 hours off from the previous day (I work, fall asleep etc) but I test alk via Hanna meter nearly everyday and vary between 9-10 routinely. LPS and soft corals could care less for sure. I only have 4 acropora frags and they don't seem to particularly care. I have 2 monti caps that do terrible and one that does ok (the one I've had the longest) which may or may not be attributed to alk swings. With that being said this isn't my first rodeo and I've had a reef with a bunch of sps, lps and zoas which I hand dosed, only tested once a week and used API dKH test which have no resolution (1dkh) and EVERYTHING did well long term so I feel like plus minutes 1dKH swings are overstated when it comes to coral health.

 

[X-37B]

That’s my gut instinct as well.

Now with a 2-3 dKH swing, that is likely more of an issue for sensitive torches and SPS I suspect?

Instant Ocean salt comes out to 10-11 dKH and most suppliers run at 8-9 dKH. Is this a major problem for those running coral QT tanks with Instant Ocean water and newly purchased corals?

I’m leaning towards changing salts if this could be the reason I just lost a gold torch.

My display runs 7-7.5 dkh but is normally around 7.2 all the time due to my carx.
My salt mixes to 9.5.
Just use sodium bisulfate to lower to desired dkh.
This is very simple to do and you wont need to change salt.

 

[Ross Petersen]

My display runs 7-7.5 dkh but is normally around 7.2 all the time due to my carx.
My salt mixes to 9.5.
Just use sodium bisulfate to lower to desired dkh.
This is very simple to do and you wont need to change salt.

Nice, I'll look into this. Many thx

Will sodium bisulfate drop pH considerably and require bubbling the freshly made water?