2 part and salinity

[Tflow256]

Can dosing 2 part cause a noticeable rise in salinity?

 

[redfishbluefish]

Without question, dosing two part raises salinity.


Now here's the reality. I've never really adjusted salinity because of dosing. I think the salt I lose from skimming balances the added salt from dosing......it's magic!

 

[Tflow256]

Ok thanks!!! I knew I read somewhere about mysterious and random increases in salinity being attributed to the starting of dosing 2 part. Someone had asked a question about their salinity creeping up after starting to dose and just wanted to make sure I was giving proper info to them. Thanks again

 

[Randy Holmes-Farley Verified Community Expert]

It is only mysterious and random if you don't expect it.

Otherwise, it is calculable and expected.

You are mostly adding sodium carbonate and calcium chloride As the calcium carbonate is removed by corals, the sodium and chloride remain.

I address it here:

https://www.reef2reef.com/blog/the-many-methods-for-supplementing-calcium-and-alkalinity/

from it:

The rise in salinity of these products over time can be very roughly calculated, though there are several reasons why this calculation is only an estimate. For every 1000 meq of alkalinity added in this fashion (and the matching amount of calcium) these products will deliver on the order of 60 grams of other ions to the tank. In a tank with a low calcification demand (defined later to be 18.3 thousand meq of alkalinity per year in a 100 gallon tank (0.4 dKH/day)) this effect will raise the salinity by 3 ppt per year (compared to a normal salinity of S ~35). In a high demand tank (defined later to be 219 thousand meq of alkalinity per year in a 100 gallon tank (4.4 dKH/day)), the salinity will rise by 35 ppt in a year, or approximately doubling the salinity. Consequently, the salinity should be monitored closely in using these types of additives, especially in a tank with high calcification rates.

 

[Tflow256]

Thanks Randy!

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Happy Reefing.

 

[zakizaka]

You're welcome.

Happy Reefing.

Reopening this thread! Any way to calculate how much ro/ di water is needed to reduce salinity from 40ppt to 35ppt? Thanks in advance!

 

[Randy Holmes-Farley Verified Community Expert]

Reopening this thread! Any way to calculate how much ro/ di water is needed to reduce salinity from 40ppt to 35ppt? Thanks in advance!

Sure, but it depends on how you do it.

Adding water then remove: You raise the total volume to 40/35 = 1.14 of what it previously was. So if total water volume is 100 L, you need to raise the total volume to 114 L, and then remove 14 L if you want.

Remove then adding water: you reduce the volume to 35/40 = 0.875 of the total current volume. So if it is 100 L, reduce the volume to 87.5 L, and then replace with RO/DI.

Of course, in neither case would you do this all at once if there are organisms present.

 

[zakizaka]

Sure, but it depends on how you do it.

Adding water then remove: You raise the total volume to 40/35 = 1.14 of what it previously was. So if total water volume is 100 L, you need to raise the total volume to 114 L, and then remove 14 L if you want.

Remove then adding water: you reduce the volume to 35/40 = 0.875 of the total current volume. So if it is 100 L, reduce the volume to 87.5 L, and then replace with RO/DI.

Of course, in neither case would you do this all at once if there are organisms present.

You’re an absolute legend thanks so much for your quick reply! I panicked and ended up adding water progressively then checking salinity. I’ve lowered it to 35ppt in about two hours ‍ Everything seems fine. Corals didn’t show any signs of being upset. Apart from my acan. Fish seem fine too. Clown fish flashed for about 10-15 minutes but they seem at ease now. Let’s see tmrw! I’ll keep you updated thanks again.

 

[zakizaka]

Sure, but it depends on how you do it.

Adding water then remove: You raise the total volume to 40/35 = 1.14 of what it previously was. So if total water volume is 100 L, you need to raise the total volume to 114 L, and then remove 14 L if you want.

Remove then adding water: you reduce the volume to 35/40 = 0.875 of the total current volume. So if it is 100 L, reduce the volume to 87.5 L, and then replace with RO/DI.

Of course, in neither case would you do this all at once if there are organisms present.

And by the way, you seem to be very very knowledgeable so while I’m here I’ll also ask you this, do you know what these are by any chance? It looks like rolled snails of some sort they’re a bit everywhere.

 

[gbroadbridge]

You’re an absolute legend thanks so much for your quick reply! I panicked and ended up adding water progressively then checking salinity. I’ve lowered it to 35ppt in about two hours ‍ Everything seems fine. Corals didn’t show any signs of being upset. Apart from my acan. Fish seem fine too. Clown fish flashed for about 10-15 minutes but they seem at ease now. Let’s see tmrw! I’ll keep you updated thanks again.

That's pretty fast, normally I wouldn't go faster than 1 psu per 24 hours.

Do everything slow in reef tanks as a general rule.

The spirals are spirobid worms. Harmless beneficial filter feeders.