High Alk---HELP

DzidtheReefer · Apr 26, 2019

Noticed on my SPS burnt tips the last week or two, but today i tested and was horrified by the results. Have had this 50gal reef tank running about 7 months, and according to my Hanna checker, first test i got was 14.9, second test 14.7, and third test 14.8. I use fritz reef salt mix and change about 20percent of water every 2 weeks. Nitrates are at 0, nitrite 0 and ammonia 0. I run a skimmer thats rated for a 150gallon tanks which i just turned off.

I do not test weekly which i do now regret, but about a few weeks ago when i did have small nitrates of 10-20 my alk was around 9.5.

What is the saffest way of slowly lowering my Alk? Should i leave the skimmer off and increase my feedings? Should i buy a dosing product that will lower my ALK slowly? ANY HELP is greatly appreciated.

Would a 20gal water change help in anyway? Calcium is 433 according to my Hanna and phosphate converted on the scale is 0.03

W1ngz · Apr 26, 2019

First thing would be to test the tester. Is there any chance you have another test kit, friend, neighbour or LFS who can confirm the value?
Mix a bucket of water and test the alk in the new water after it's been allowed to mix for 24 hours so that it equalizes pH and CO2 with the room the tank is in.

If you confirm the test is accurate and that new water is at a more acceptable level, a few larger than normal water changes over several days will bring it back in line. Best to do it slowly. Sudden alk swings are worse than high alk for most of your tank.

W1ngz · Apr 26, 2019

Oh, and if you're dosing anything, stop that too until you sort out the issue.

DzidtheReefer · Apr 27, 2019

Currently ALK is 14.6, new batch of saltwater mixed to 1.026 thats been mixing for 5 hours is reading ALK 9.0, 8.8, and 9.0 pretty consistent to what others are getting.

What can cause ALK to be so high? I am stumped? The tank does get sunlight everyday, no algae issues, i vacuum sand every water change.

W1ngz · Apr 27, 2019

As far as I'm aware, the only way alk can increase is by adding buffer, or you had a weird batch of salt, perhaps a big clump of something that never got mixed.
Do you dose anything at all? Anything that might raise alkalinity or is intended to manipulate pH?

The only way to lower it is water changes and for corals and coralline algae to consume it. Consumption by corals and precipitation may be faster if you also increase the calcium levels up closer to 480-500

W1ngz · Apr 27, 2019

https://www.advancedaquarist.com/2002/11/chemistry

The Opinionated Reefer · Apr 27, 2019

Have you let your salinity increase significantly?

RJ F. · Apr 27, 2019

Something has to be causing these high alk increases. Normally salt or a 2 part. The only way to lower it safely is by what the others have said. Water changes over DAYS. normally 1 dkh over the whole day is acceptable. However you are going for a significant decrease. 12 dkh is acceptable for a reef tank so I would shoot for that for now. Then figure out what your alk goal is from there. Alk stability is very important. So getting to an acceptable range then keeping it there would be the end goal imo. Track your alk for a couple weeks to find the trend.

DzidtheReefer · Apr 27, 2019

Currently ALK is 14.1, skimmer has been turned off since yesterday. I have increased feedings to 3 times a day now. No water change yet, i do not want to shock the system and it has fallen a good amount already.

For filtration I only run 3sheets of filter pad, inbetween that is chemipure elite and a oversized skimmer. I do not have an ATO or a doser, but i do add 5cups of RODI water a day which keeps the system stable enough. This setup i keep simple as possible but i am puzzled on how ALK could have risen so high.

Thanks for all the replies, tommorow i will perform a 10gal water change and go from there

W1ngz · Apr 27, 2019

Feeding, filtration and skimmer have no effect on alkalinity. It would be best to not change the rest of the tank's routine right now.

RJ F. · Apr 28, 2019

W1ngz said:
Feeding, filtration and skimmer have no effect on alkalinity. It would be best to not change the rest of the tank's routine right now.

I agree. Stability over everything. Too many changes at once will make a tank crash faster than a baby drinking warm milk.

Randy Holmes-Farley · Apr 28, 2019

W1ngz said:
As far as I'm aware, the only way alk can increase is by adding buffer, or you had a weird batch of salt, perhaps a big clump of something that never got mixed.
Do you dose anything at all? Anything that might raise alkalinity or is intended to manipulate pH?

The only way to lower it is water changes and for corals and coralline algae to consume it. Consumption by corals and precipitation may be faster if you also increase the calcium levels up closer to 480-500

Alk can rise without dosing (such as by nitrate consumption) , and it can be lowered by using alk lowering products such as muriatic acid or sodium hydrogen sulfate.

Randy Holmes-Farley · Apr 28, 2019

Mirzet besic said:
Noticed on my SPS burnt tips the last week or two, but today i tested and was horrified by the results. Have had this 50gal reef tank running about 7 months, and according to my Hanna checker, first test i got was 14.9, second test 14.7, and third test 14.8. I use fritz reef salt mix and change about 20percent of water every 2 weeks. Nitrates are at 0, nitrite 0 and ammonia 0. I run a skimmer thats rated for a 150gallon tanks which i just turned off.

I do not test weekly which i do now regret, but about a few weeks ago when i did have small nitrates of 10-20 my alk was around 9.5.

What is the saffest way of slowly lowering my Alk? Should i leave the skimmer off and increase my feedings? Should i buy a dosing product that will lower my ALK slowly? ANY HELP is greatly appreciated.

Would a 20gal water change help in anyway? Calcium is 433 according to my Hanna and phosphate converted on the scale is 0.03

High alk by itself is not generally a cause of burnt tips.

High alk and low nutrients can be. I didn’t see a nitrate measurement, but it may be too low.

W1ngz · Apr 28, 2019

Randy Holmes-Farley said:
Alk can rise without dosing (such as by nitrate consumption) , and it can be lowered by using alk lowering products such as muriatic acid or sodium hydrogen sulfate.

I stand corrected sir!

Thanks for all your input over the decades. You're probably responsible for 90% of the knowledge the rest of us throw around.

DzidtheReefer · Apr 30, 2019

Nitrates were at 0 when it tested at 14.9. Since than i have turned off my skimmer and have started feeding alot more. I am at work now, but yesterday around 5pm it tested at 13.4 and nitrates are around 5. When ALK goes to 12 i will than do a water change.

And yes randy, i turned off my skimmer and started feeding more when i did some research and found a thread you suggesting that ALK spikes when nutrient levels fall.

I DO NOT dose anything, only thing i ever changed in the last 2months is this oversized skimmer i am using

Crustaceon · Apr 30, 2019

It sounds to me like your best course of action would be to feed your fish as normal, sit back and don’t touch the tank otherwise for the next few weeks. Alkalinity will fall and nitrates will rise naturally.

Cassian · Apr 30, 2019

I just had the same problem. I got lots of good suggestions. It turned out my problem was I needed to use RODI water. Here's the link so you can read what was going on and see the suggested solutions. hope this helps!
https://www.reef2reef.com/threads/how-to-improve-sps-color.587417/