Help, high alkalinity

[Chuckycole]

I have a new 20 gal mixed reef tank all my levels are normal except my alkalinity is is at 14+ dkh is there anything I can do to help lower it

[Troy Valentine]

Welcome to MAAST!

What brand salt are you using? Assuming the ALK levels are within range (>10dkh preferably around 8)in your salt mix. Then I would do a 5 gallon water change or 25% of your system. If your salinity is a little high, I would lower the salinity of your water change water a bit. From 35ppt to 31ppt depending on your current salinity.

[Troy Valentine]

But first I would find out what the ALK level is of your salt mix.
www.google.com/amp/www.saltwateraquariumblog.com/best-aquarium-salt-mix-review-popular-reef-salt-mix-options/amp/

[Chuckycole]

Salinity is at 1.024 and I buy saltwater premixed from fish store just done a 5 gallon water Change yesterday and no change from before water change to after about 3 hours later. calcium is at 420, ph is 8.0 nitrite is 0, nitrate is about 10, mag is around 1300, ammonia is 0, it's just the alk that keeps going up last week it was 11 and now is at 14 dkh

[Sierra_Bravo]

Are you dosing anything?

If you aren't dosing anything there are not a lot of reasons for your Alk to rise like that. I would buy another test kit to make sure you don't have a bad one and if you're still getting those numbers the next suspect would be the saltwater from your LFS. Test it as others have suggested to see what it's sitting at before you add it.

[FarmerTy]

Agreed with all the advice above. If you don't dose anything and only do water changes, then the saltwater you buy from the store is the culprit. More than likely they are using some type of "pro" brand what has higher alkalinity in it, such as Red Sea Pro salt.

If they have regular salt (like Instant Ocean or some other cheap brand), I'd switch to that as the alk is generally lower. The "pro" salts have higher alkalinity for when your tank is stocked and the corals use up the Ca, alk, and Mg, it can help replenish and keep up with coral demand.

Unfortunately, it'll take you forever to lower you alk via water changes as trying to lower 14 dKh with 12 dKh is not really that practical. Even with regular salt which may have 8 dKh would would take forever too. You could change 50% of your water with 8 dKh water and you'd still be at 11 dKh!

You can lower it quicker by introducing muriatic acid, but just be careful and add it to the sump very slowly if you have one. Make sure you wear gloves and eye protection. You can also just add it to the new saltwater to depress the alk before doing a water change, to make it more effective in lowering your tank alk.

In either case, test lots, and go slowly. Ideally you don't want to change alk levels more than 1.5 dKh/day. Good luck!

[Chuckycole]

Thanks for all the help so far guys, I dose kalk+2 as needed my calcium doesn't drop very fast, so I test every few days and always on Sunday when I do water changes and maintenance I drip a very small amount and check it a few days later to see where it's at so far I haven't dropped below 400, everything in the tank seems to be thriving, it's just the alk stays high, I will see what my lfs is using and my just start mixing my own, I will keep you updated thanks again for the info