Soda ash dose not matching calculations

[captain_jimmy]

Hi there

I have started dosing soda ash to try and keep my alk stable.
I've been using the brs calculator with the dry soda ash option selected.

The amount it tells me to dose to raise the dkh to my desired level is not giving the expected results. It's raising it approximately half of what is expected.

So I am wondering why?

Measurements are through a new Trident that was recently calibrated.

As an additional question...
My calcium is also kinda high at 520 and I've no idea why. It's currently 520 and I did a 40% water change with tropic Marin pro yesterday so would have expected it to come down somewhat. Looking at my graph it did come down to 497 at the water change but then drifted back up.

I have very high phosphate levels at the moment, around 0.25 (bringing them down slowly). Wanted to mention this.

Thanks everyone.

 

[DrZoidburg]

Are you sure its not the bi carb calculator? That would take a bit more to raise it to target. If 2 part is out of balance you could run into high or lower number with one or the other. Try dialing it back a little bit. 520 calcium is not really a big problem. Maybe just need fine tuneing.

 

[captain_jimmy]

Yeah pretty sure.
Using this link..

Alkalinity Supplement Calculator - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

I selected brs dry soda ash.

I need to raise it again this evening so I'll do it again and document the change and report back.

Ok good to hear about the calc levels. I am wondering why they are raising though, I'm not dosing calc.

Mag is 1119 ftr.

 

[DrZoidburg]

Maybe over dosed, maybe heavy handed mixing it, maybe out of balance. Maybe trident error I dont knot. Would be good to at least dial it back, and focus on keeping alk as stable as possible. Could compare with normal test kits if you have.

 

[DrZoidburg]

My thought are usually because the calculator is within a certain amount. 1: either you used the wrong calculator. 2: maybe mixing error. 3: maybe mixed in the bicarb instead of carbonate. Those would all show close to half expected amount. Other wise I cant say for sure. If things are not using calcium that could rise. Like in a situation where you have a new tank with algae, or in situation where you have a anaerobic bacteria filter. These can use 2x the alkalinity and no calcium.

 

[Randy Holmes-Farley]

What exact material (brand, etc) are you using?

How are you dosing it?

How large of a boost are you expecting and getting?

How long after dosing are you measuring?

Try this calculator:

Reef Chemistry Calculator

 

[R33f]

What exact material (brand, etc) are you using?

How are you dosing it?

How large of a boost are you expecting and getting?

How long after dosing are you measuring?

Try this calculator:

Reef Chemistry Calculator

Hello
I am currently trying to startup with Alkalinity in my tank. I have KHG which auto corrects Alk in the tank. It directs to use Sodium Bicarbonate mix 65 Grams to 1 litre for the accuracy of its Alk accuracy.
For now I have BRS Soda Ash powder. I am unable to get the concentration to the above KHG instructions.
Also my tank is not so high on PH so this solution suits the tank parameters. I cannot formulate the accuracy to the solution. I would be grateful if you could guide me with something for me to solve it.
Sorry for being off topic from this thread but I don’t know much how to get an answer.
Thanks

 

[captain_jimmy]

What exact material (brand, etc) are you using?

How are you dosing it?

How large of a boost are you expecting and getting?

How long after dosing are you measuring?

Try this calculator:

Reef Chemistry Calculator

Hi, I totally missed this reply until someone else replied last Friday.

I am using brs soda ash powdered form.
I am using the brs alkalinity calculator.
I'm mixing with some rodi water and adding to the tank. The first couple of times I just added it all but got a pH spike so the following few times I added half the. Put the rest in the rodi unit so it would be dosed more slowly.

An example of the estimates the calculator returned compared to what actually happened:

I entered 100g volume
Want to take alk from 7 to 8.4
Calculator says 2.18 tsps of soda ash
I mixed with approx 1 qt rodi water and added to sump in return pump chamber
Alk went to approx 7.7 instead of the expected 8.4

I added a trident a month or two back so it measures continuously, shows the increase on the next test then slowly tapers as normal.

I'm still away on business but will do some more controlled tests once I'm back this week and report back.

 

[Randy Holmes-Farley]

Hi, I totally missed this reply until someone else replied last Friday.

I am using brs soda ash powdered form.
I am using the brs alkalinity calculator.
I'm mixing with some rodi water and adding to the tank. The first couple of times I just added it all but got a pH spike so the following few times I added half the. Put the rest in the rodi unit so it would be dosed more slowly.

An example of the estimates the calculator returned compared to what actually happened:

I entered 100g volume
Want to take alk from 7 to 8.4
Calculator says 2.18 tsps of soda ash
I mixed with approx 1 qt rodi water and added to sump in return pump chamber
Alk went to approx 7.7 instead of the expected 8.4

I added a trident a month or two back so it measures continuously, shows the increase on the next test then slowly tapers as normal.

I'm still away on business but will do some more controlled tests once I'm back this week and report back.

The calculations seem correct. Do you see any signs of local precipitation in the sump where you mix in?

What brand of sodium carbonate?

If the 7.7 dKH is soon after mixing in, then I suggest using baking soda instead to reduce chances of precipitation.

Maybe your volume estimate is off, or the sodium carbonate is not as dense as expected (more fluffy).