Question For Randy

[Rickyrooz]

Hi Randy,
I mixed up a new batch of Instant Ocean sea salt (30 gallons) and the results were as follows:

pH - 7.8
Salinity - 1.0265 (35 ppt)
Alkalinity – 10.4 (Salifert) 7/19 exp. Too High
Calcium – 460 (Salifert) 8/19 exp. Too High
Magnesium – 1290 (Salifert) 4/16 exp.
Potassium - 325 (Salifert) 10/15 exp. Too Low
Phosphate – 0.13 (Hanna) 12/15 exp. Too High
Fresh RO/DI water tested at Phosphate – 0.05 (Hanna) 12/15 exp. Too High

My question is how can I lower the alkalinity of the new salt before adding it to my display? I currently run ZEOvit and want the parameters as close as possible to NSW. I have been using Tropic Marin Pro Reef sea salt but my LFS was out of stock and only had the IO salt.

 

[redfishbluefish]

I know your looking for a Randy answer, but two thoughts:

Even an alkalinity of 1 or 2 dkh above target levels within the new water, with a 30% or less water change, the impact on total dkh will be minimal, and with a typical reef tank, that will be "consumed" within the first day.

And Randy will most likely ask this....how soon after mixing are you testing? I would recommend mixing unheated for at least a day and then testing to get a more accurate number (allow everything to dissolve).

 

[Rickyrooz]

I know your looking for a Randy answer, but two thoughts:

Even an alkalinity of 1 or 2 dkh above target levels within the new water, with a 30% or less water change, the impact on total dkh will be minimal, and with a typical reef tank, that will be "consumed" within the first day.

And Randy will most likely ask this....how soon after mixing are you testing? I would recommend mixing unheated for at least a day and then testing to get a more accurate number (allow everything to dissolve).

I mixed the water for 12 hours before testing, temperature was 78 degrees.

 

[Randy Holmes-Farley]

IMO, people worry too much about the parameters in their new salt water.

A 10% change in a tank at 7.4 dKH using water with 10.4 dKH will only boost the alkalinity to 7.7 dKH.

I also don't consider the calcium or phosphate to be any issue. With respect to phosphate, you'll add 1000 times that amount EVERY day in foods, so keep that perspective.

But, if you want to reduce alkalinity, muriatic acid is a fine way to do it in a batch of new salt water.

 

[Rickyrooz]

IMO, people worry too much about the parameters in their new salt water.

A 10% change in a tank at 7.4 dKH using water with 10.4 dKH will only boost the alkalinity to 7.7 dKH.

I also don't consider the calcium or phosphate to be any issue. With respect to phosphate, you'll add 1000 times that amount EVERY day in foods, so keep that perspective.

But, if you want to reduce alkalinity, muriatic acid is a fine way to do it in a batch of new salt water.

Thank you, how much muriatic acid should I use? I have a gallon jug of it from a pool supply store. I use it for cleaning my pumps and skimmer once a year. Will there be side effects of dosing muriatic acid into the new saltwater and then adding the new water into a tank full of fish and coral?

 

[Randy Holmes-Farley]

Here's a thread on using muriatic acid as well as other products to lower alkalinity. The side effect is very low pH, which will rise again if you aerate it sufficiently:

https://www.reef2reef.com/threads/h...lower-alkalinity-like-you-can-with-ph.188293/