Mixing kalk with SW to raise salinity

[Texanjordan]

My salinity on my reef tank has dropped to 1.20, seems like my salinity has started dropping since I started dosing kalk two weeks ago. I want to raise my salinity back to 1.25, can I mix kalk with saltwater to raise the levels and still continue with the kalk?

 

[Rain999]

It sounds like you are adding more kalk water than you are evaporating from the tank. I would reduce the rate of kalk water I was adding to the tank.

 

[mtrcyclefish]

Someone will correct me if I'm wrong, but I'm pretty sure that kalk will not dissolve properly into salt water. Otherwise we could just add dry kalk to our sumps instead of having to dose it with the topoff water. Check your skimmer. If your skimmate is too wet it will cause your topoff to add more fresh water while the skimmer is removing salt water.

 

[skunkmere]

i dont think that kalk lowers your SG. I used it and never seen that, i may be wrong. what are you using to test your SG, is it accurate? you can add kalk directly to your tank, but the problem is ph, it will make your ph skyrocket and kill stuff. you need to dilute it and drip it in or use a ATO so the PH doesnt spike so high.

 

[DragonWarriorPo]

+1. How do u check your salinity? It shouldnt drop with kalk. And you will see your sump level rise if you are topping off too much

 

[Texanjordan]

I check my salinity with a refractometer. My sump is on an ATO, and I have a sensor to make sure it doesnt dump to much RODI in my sump. Since I have been dosing kalk, I have been using very little of RODI from my ATO. My Skimmer has been acting up for the last few weeks, got it working right this last few days, so I have had it running uncapped, so skimmate going crazy and making my ATO kick on is not an issue. My tank looks awesome even though my salinity is 1.20, I will try and check salinity water from mid tank and not the top when i get home. I just want a good way to raise my salinity, normally I would raise it by putting saltwater in my ATO, but since that is not running very often due to my drip dosing, that wouldent be a good option. and I am only dosing about 1 gallon in 2 days, and on a 90 gallon tank with a 25 gallon sump, I dont think that I am overdoing it. I think my evap rate is around .5 gallons a day

 

[Timber77]

just mix water and salt...and get your balance right...the kalk doesnt affect salinity

 

[Spartanman22]

Kalk will dissolve just fine in salt water but you will not like the results. Kalkwasser is fairly soluble and if it was dumped directly into the tank as opposed to adding it in dilute amounts through top off, then you will experience a very large and dangerous pH spike. A saturated lime water solution has a pH of roughly 12-13. The kalkwasser when dissolved in salt water will also result in a high localized calcium concentrations. This will lead to the precipitation of calcium carbonate. So, you would actually be loosing more calcium carbonate to precipitation than you'd be gaining. Kalk will not affect salinity as others have stated. You noted that your skimmer was acting crazy in the previous couple of weeks but you have it running fine now. Do you have your skimmer waste draining to a container? If so was your skimmer overflowing resulting in a lot of waste causing the ATO to kick on and ultimately lowering your salinity? Your best bet would be to just do a water change to fix the salinity. I'd do it over a couple changes over the course of the week as to not shock anything.

 

[skunkmere]

i would add a 1/4c of salt to the sump every day until its good. or less

 

[E Rosewater]

Do you have a lot of salt creep? If your losing water from splashing rather than evaporation then adding freshwater it will bring down the salinity.

Mixing a salt mix with Kalk will crash out calcium carbonate at those pH levels.

 

[E Rosewater]

Also if the skimmer was going to crazy you could be losing salt water to the skimmer and replacing it with fresh water.

 

[acasp4]

I didn't feel like reading all the replies so excuse me if Im repeating someone lol. Texanjordan your title states that your mixing kalk into SW if thats what your doing you CAN NOT mix kalk into saltwater, Mixing Kalk powder into saltwater will precipitates Ca out of the SW and your skimmer is just sucking it up doing nothing for your tank. Kalk powder must be mixed into freshwater to be affective. CHEM 411 UW-Madison

 

[Texanjordan]

my skimmer was overflowing like crazy, but i had the drain plug out so it was drainign back into the sump. So water did not come out of my system. I checked mid tank last night and i was at 1.21. Someone suggested adding 1 cup of salt right in my sump, has anyone done this method before? I thought you were never supposed to add salt straight to your water. Im also a little confused about why you cannot mix kalk with salt, I have a drip dosing system from DFS, and it drips very slowly, it wont cause a PH spike, but raise it slowly over time. The container drain for the drip is about an inch off the bottom, so none of the slurry actually makes it in my system. And the container is sealed, so how am I loosing Ca from the water?

 

[E Rosewater]

At basic pH, which you would get by mixing salt mix and Kalk you would crash out the calcium as calcium carbonate.

Now this would be a different story if you were mixing pure salt (rather than a salt mix) which doesn't contain the calcium source and carbonate source.

 

[Spartanman22]

As rosewater stated the issue with slowly dropping it in isn't a pH issue it would precipitate out calcium carbonate which is the opposite of what you are wanting to do. It would basically be a wasted effort ecause you wouldn't be adding any appreciable amount of useable calcium because it would all be precipitating out of solution.

 

[Texanjordan]

For what it's worth, I dumped out the kalk salt mix and made another batch with just RODI and kalk. I added about 4 cups of salt to my sump allready dilluted, it didn't seem to raise my salinity much, it's at 1.23 but it probably takes a little bit to get thru the whole system.