Alk drop

[hadams356]

Will someone help and explain to me in layman terms why alk drops everytime I make new batch of 2 part. I am dosing Jim Welch's high pH solution and mixing it accordingly everytime using digital scale.
Alk will maintain 8.5 using Trident and shows up as 9.1 using Hanna. But after a day or so alk drops to around to 6.71 on Trident and 7.3 on Hanna causing me to supplement alk over days to get it to raise. Once raised alk will maintain for a couple of weeks until new batch.
This happens everytime I mix new batch. Again I mix according to recipe and afraid to mix to B-Ionic value due to higher PH value.
Any help would be greatly appreciated.

 

[Randy Holmes-Farley]

Will someone help and explain to me in layman terms why alk drops everytime I make new batch of 2 part. I am dosing Jim Welch's high pH solution and mixing it accordingly everytime using digital scale.
Alk will maintain 8.5 using Trident and shows up as 9.1 using Hanna. But after a day or so alk drops to around to 6.71 on Trident and 7.3 on Hanna causing me to supplement alk over days to get it to raise. Once raised alk will maintain for a couple of weeks until new batch.
This happens everytime I mix new batch. Again I mix according to recipe and afraid to mix to B-Ionic value due to higher PH value.
Any help would be greatly appreciated.

Can you clarify what you are experiencing? I'm not really clear on what you are observing.

Are you suggesting the first day you dose a new batch you get one level of alk boost, and later you get a smaller alk boost from the same addition?

Or are you suggesting that after you dose, alk continues downward when there is no additional dosing?

The latter is certainly normal. Most folks dose every day.

Again I mix according to recipe and afraid to mix to B-Ionic value due to higher PH value."

I do not understand what that means. My hydroxide recipes have a potency that is intentionally lower than B-ionic, but could be higher if that was a goal.

 

[hadams356]

Thanks for reply, I dose continuously using dosing pumps, set to 300 ml per day, system is 220 gallon including sump.
Alk will run at 8.5 according to Trident but mix new batch and alk drops to around 7. Happens everytime, don't understand why. Therefore, I have to supplement alk over days to get it back up.
Alk never runs dry always remix new batch before dosing container is empty. 1 gallon of alk last about 2-1/2 to 3 weeks. Ca and mg doesn't seem to be affected with new batch. Pics of what I am using.

 

[Randy Holmes-Farley]

Are you tracking pH? Does the pH get higher with a new batch than with an old batch that may have been exposed to CO2 longer?

 

[hadams356]

Yes, it raises to about 8.45 for day or two then level off to 8.30's. Drops .25 to .30 at night

Just ran parameters with Apex 12 pm ET
Alk 7.06
Ca. 426
Mg 1365
Temp. 79.9
PH 7.92
Orp 363
Salanity 35.3

DOS says
302ml Alk added last 24hrs
374ml Ca/Mg added last 24hrs

 

[hadams356]

Yes, it raises to about 8.45 for day or two then level off to 8.30's. Drops .25 to .30 at night

Just ran parameters with Apex 12 pm ET
Alk 7.06
Ca. 426
Mg 1365
Temp. 79.9
PH 7.92
Orp 363
Salanity 35.3

DOS says
302ml Alk added last 24hrs
374ml Ca/Mg added last 24hrs

Also run Co2 Reactor with soda lime.
I do weekly water changes of about 30 gallons.

 

[Randy Holmes-Farley]

Yes, it raises to about 8.45 for day or two then level off to 8.30's. Drops .25 to .30 at night

Just ran parameters with Apex 12 pm ET
Alk 7.06
Ca. 426
Mg 1365
Temp. 79.9
PH 7.92
Orp 363
Salanity 35.3

DOS says
302ml Alk added last 24hrs
374ml Ca/Mg added last 24hrs

If the pH is initially higher in the tank and alk is lower, that suggests that the pH potency of the product is declining over time as CO2 enters it. That doesn't impact the alkalinity potency, but it does reduce the pH effect.

The higher pH will tend to drive higher consumption of alk, and hence your need for additional alk.

This all makes sense, but I do not know if it is the explanation or not.

Is the alk solution open to the air as it sits waiting to dose? Are any solids appearing in it that were not there initially on mixing up?

 

[hadams356]

No, not really. I use 1.5 gallon plastic jugs and drilled hole in lid for a pice of rigid tubing.

 

[hadams356]

No, not really. I use 1.5 gallon plastic jugs and drilled hole in lid for a pice of rigid tubing.

No it mixes up very clear so to speak. When dosed forms cloud in sump water as it should.

 

[hadams356]

Corals are growing but absolutely no color.

 

[Randy Holmes-Farley]

No, not really. I use 1.5 gallon plastic jugs and drilled hole in lid for a pice of rigid tubing.

That should be fine.

 

[hadams356]

Do you have any suggestions as to how I fix this roller coaster?

When I use baked baking soda pH barely makes it to 8.15. At night it would fall down to low 7's sometime high 6's. That was the reason I started uses the higher pH solution.

 

[hadams356]

Just FYI I live in Florida so having doors and windows open are rare occasions

 

[Randy Holmes-Farley]

Are you certain the alk drop does not relate to air in the dosing line delaying dosing for a bit?

 

[hadams356]

I changed tubing to RedSea on intake line with clean lines on outflow. Thought same thing. See an occasional air bubble e ery couple days or week but not to the point where it would influence it this much. Have also checked the DOS calibration and it's right on the money.

 

[Randy Holmes-Farley]

How much does the alk drop in the first few days if you do not add any extra alk?

 

[hadams356]

Been as low as 5.95 but normally low 7's high 6's. Once I get it up to 8.5 it maintains dosing 300ml per day. It's only when new batch is mixed it drops. Tried dosing kalk at night but seem like it got everything out of wack.

 

[Randy Holmes-Farley]

Been as low as 5.95 but normally low 7's high 6's. Once I get it up to 8.5 it maintains dosing 300ml per day. It's only when new batch is mixed it drops. Tried dosing kalk at night but seem like it got everything out of wack.

I don't really understand this and am leaning toward some sort of mechanical or interference effect. I've never heard of anyone experiencing what appears to be increased potency over time.

 

[hadams356]

I will be mixing new batch of 2 part in next couple days will keep you posted.

 

[hadams356]

Hi Randy, we spoke a week or so ago regarding alk dropping. I changed 2 part and went back to Recipe 1 ( baked baking soda) I guess it was percipating out. Alk seems to be holding steady.
My one question is can I use the the cal/mg recipe the one that has cal/mg mixed together or do I need to go with the 3 part recipe? Sure like the convenience of the 2 part.