Confused about my PH and KH....

[Hugo_Fish]

Hey guys!

Tank size: 10 Gallon
Salt Mix: IO Reef Crystals mixed to 35ppt

I am noticing that even at mixing I am getting low PH and KH.. currently sitting a 6.86kh and 7.7PH. close to the desired numbers for the hobby I know, but I kind of want my Kh to be at 9 and stable and a boot to my PH would also be nice. I am unsure what I to do at this point because I do not believe my corals are taking enough out of the water to justify adding chemicals.


Question: what should I do to raise my KH ...
A. slowly increase KH and PH during the mixing process of the water change.
B. add something to my ATO.
C. Start dosing.
D. Change Salt <--- but to what? I am noticing that salt mixes are premixed at 8 or 11. and IO is stating it's mixed at 8kh...

As for testing, I am using Red Sea for KH and PH I am using my Apex and Milwaukee mc122 both were calibrated 2 nights ago.

 

[Randy Holmes-Farley]

A few comments.

That alk is OK and you do not necessarily need to raise it, but raising it is Ok as long as you know it is accurate. Baking soda is a fine way to do that.


Reef Crystals is a high alk mix. Getting a low value for testing it may mean:

1. the test kit is giving incorrect results,
2. there is a large amount of calcium carbonate precipitate in the mixing barrel,
3. the salinity is far lower than you think
4. the salt itsely was separated in shipping so the ingredients were not homogeneous in the bucket
5. it was a bad batch
6. The water used had an issue where it had some acidity

I list those in a rough order of likelihood of being the explanation (IMO), but it may also be a combination of several

The pH is driven by alk and the CO2 level in your home air. I would not focus on it in new salt water.

 

[Hugo_Fish]

mmm, I will see about buying a new ALK test kit and a new refractor. been wanting to upgrade to a Milwaukee. As for PH I have been testing a C02 scrubber and have noticed that it is more steady. but I fear that might be a placebo.

Baking soda is a fine way to do that

wouldn't baking soda lower PH?

 

[TX_REEF]

what's your mixing procedure? I use IO regular salt, I leave it to mix with a powerhead in a trash can overnight. IO can take longer than other salts to dissolve, so the old mix with a wooden spoon in a bucket for 5 mins technique isn't ideal.

Definitely don't add anything to your ATO, as evaporation is not 100% constant.

 

[Randy Holmes-Farley]

wouldn't baking soda lower PH?

Not noticeably. The effect is very small.

 

[Hugo_Fish]

what's your mixing procedure? I use IO regular salt, I leave it to mix with a powerhead in a trash can overnight. IO can take longer than other salts to dissolve, so the old mix with a wooden spoon in a bucket for 5 mins technique isn't ideal.

Definitely don't add anything to your ATO, as evaporation is not 100% constant.

I work nights and my water changes (3 Gallons) and they are done on Monday. I start my RODI unit the day before and when I get home I put in 480 grams of IO and let it mix with a heater and pump while I am asleep. I do the water change late Monday night.

 

[Hugo_Fish]

Not noticeably. The effect is very small.

I'll get a Hanna and go off of that .. Remembering what I tested the colors are hard to see... like the green isn't that green..

 

[jda]

I have used IO for more than 30 years. I don't care what anybody says, unless you use the whole container, the mix can settle. I usually use the whole bag, or my tanks are large enough that outlier parameters dont move a thing if I do not dry mix the salt. However, if I need a dead-on-balls fresh saltwater batch, I dry mix the salt for a few minutes.

Usually with overnight mixing, the pH in my fresh IO is the same as my display tanks when the lights are off (no photosynthesis boost). This is likely all from the ambient co2 in the air... right now at 441 ppm (glances at co2 meter,) which is low for indoor levels.

 

[Hugo_Fish]

Not noticeably. The effect is very small.

@Randy Holmes-Farley forgot to ask... so PH is driven by C02 and alk... if using baking soda, how long would it take for PH to go back up because of the change of Alk from the baking soda? are we talking about hours or days?

never used baking soda or Soda Ash before so I'm unsure what I will see. My new hanna alk test will be here Sunday so I will see what my alk is. hopefully my question makes since.

 

[Randy Holmes-Farley]

@Randy Holmes-Farley forgot to ask... so PH is driven by C02 and alk... if using baking soda, how long would it take for PH to go back up because of the change of Alk from the baking soda? are we talking about hours or days?

never used baking soda or Soda Ash before so I'm unsure what I will see. My new hanna alk test will be here Sunday so I will see what my alk is. hopefully my question makes since.

Adding baking soda (bicarbonate) causes a very small change in pH (lower) and alkalinity (a rise) instantly. Over a period of time the pH recovers back towards where it was, or a tad higher, depending on how much alk you added. The time period is likely hours but depends entirely on your tanks aeration capacity and the home air CO2 levels.

Adding washing soda (soda ash/carbonate) causes a rise in pH and alkalinity instantly. Over a period of time the pH recovers back towards where it was, or a tad higher, depending on how much alk you added. The time period is likely hours but depends entirely on your tanks aeration capacity and the home air CO2 levels.

Adding hydroxide (limewater or sodium hydroxide) causes a bigger rise in pH and alkalinity instantly. Over a period of time the pH recovers back towards where it was, or a tad higher, depending on how much alk you added. The time period is likely hours but depends entirely on your tanks aeration capacity and the home air CO2 levels

I discuss these issues in much more detail and give some experimental results here:

Chemistry And The Aquarium: The Relationship Between Alkalinity And pH

Randy answers many questions in this complex relationship.

reefs.com

 

[Hugo_Fish]

how much alk you added. The time period is likely hours but depends entirely on your tanks aeration capacity and the home air CO2 le

thank you Randy !!

Yeah, I just checked my alk again with my new Hanna.. it's stating 6.8Dkh. If people are saying that IO mixes high when it comes to Alk, I am wondering if either my ATO water has low alk ...or it's a bad batch... granted tomorrow is my water change night but I do not think my corals are using that much Alk ... I will further monitor and see what happens over next week.



If I am using baking soda and do not have a sump ... where do you believe is best to dose? I kind of want to dose in the back of the AIO as if I use my power head I feel I will blast my corals. but if I dose it in the back I fear the flow isn't fast enough. or should I use Limewater? Kind of do not want to mess with other parameters as they are good.

 

[Randy Holmes-Farley]

Dose slowly to a high flow area away from organisms.

 

[rennjidk]

thank you Randy !!

Yeah, I just checked my alk again with my new Hanna.. it's stating 6.8Dkh. If people are saying that IO mixes high when it comes to Alk, I am wondering if either my ATO water has low alk ...or it's a bad batch... granted tomorrow is my water change night but I do not think my corals are using that much Alk ... I will further monitor and see what happens over next week.



If I am using baking soda and do not have a sump ... where do you believe is best to dose? I kind of want to dose in the back of the AIO as if I use my power head I feel I will blast my corals. but if I dose it in the back I fear the flow isn't fast enough. or should I use Limewater? Kind of do not want to mess with other parameters as they are good.

I've had issues with IO being all over the place. A lot of people like it because it's been around forever.

With the recent price hikes and an MSRP of $79.99 a bucket, there's really no reason to continue using it, especially when ICP tested salts (NYOS, AF) sell for $10 more and have better parameters for a reef tank (IMO). Especially in nano tanks like ours, where a bucket is a 1-2 year expense.

Just my two cents...