Alkalinity issue ongoing for months, help!

Donald Wright · Jan 8, 2019

I have a 220 reef, full of live rock, few pieces of soft corals, no hard corals and a few fish. Water is at 1320 Mag, 460 Cal, PH between 8.0 and 8.2, No Phosphates, Salt at 1.026, temp stays at 25 Celsius. I have a drip set up for Kalkwasser that maintains my Calcium between 440 and 460.My Alkalinity will only stay at 6.66 by adding a constant drip of Liquid Soda Ash at twice what it should be to maintain a 1.4 Alk raise per day. Issue is if I keep this constant drip it never goes over 6.6 and I start seeing a build up of white deposits on pumps, heaters, and in my Protein Skimmer. I have to set the drip a the correct amount of ml for 1.4 rise of Alkalinity and the Alkalinity will go down to around 4.8 to 5.2. I have not lost any coral or fish at this low level but some corals have shrunk. I have tried two part solution of Sodium Bicarbonate also with no luck, just goes up and drops as soon as I stop huge amounts of solution. I have fresh water top off coming thru RO unit to sump that is 7ph. My PH has leveled out with running C02 remover media on the skimmer.
Any advice on how to get the Alkalinity up to 8 or 9 and stay there would greatly help.

saltyfilmfolks · Jan 8, 2019

What Is the ph at ?

#reefsquad
@Randy Holmes-Farley

Brew12 · Jan 8, 2019

Donald Wright said:
I have a 220 reef, full of live rock, few pieces of soft corals, no hard corals and a few fish. Water is at 1320 Mag, 460 Cal, PH between 8.0 and 8.2, No Phosphates, Salt at 1.026, temp stays at 25 Celsius. I have a drip set up for Kalkwasser that maintains my Calcium between 440 and 460.My Alkalinity will only stay at 6.66 by adding a constant drip of Liquid Soda Ash at twice what it should be to maintain a 1.4 Alk raise per day. Issue is if I keep this constant drip it never goes over 6.6 and I start seeing a build up of white deposits on pumps, heaters, and in my Protein Skimmer. I have to set the drip a the correct amount of ml for 1.4 rise of Alkalinity and the Alkalinity will go down to around 4.8 to 5.2. I have not lost any coral or fish at this low level but some corals have shrunk. I have tried two part solution of Sodium Bicarbonate also with no luck, just goes up and drops as soon as I stop huge amounts of solution. I have fresh water top off coming thru RO unit to sump that is 7ph. My PH has leveled out with running C02 remover media on the skimmer.
Any advice on how to get the Alkalinity up to 8 or 9 and stay there would greatly help.

Very odd situation. Any chance your Magnesium test may not be accurate? I don't see any reason your alkalinity would precipitate out at the numbers you are using.

Any chance your alkalinity test reads in meq/L instead of dKH?

reeferfoxx · Jan 8, 2019

If you aren't reading the measurement incorrectly, i would use a second newer test kit to verify alk levels.

TheEngineer · Jan 8, 2019

reeferfoxx said:
If you aren't reading the measurement incorrectly, i would use a second newer test kit to verify alk levels.

+1

rkpetersen · Jan 8, 2019

All test results should be confirmed. I'd then raise the magnesium which may keep some of the calcium carbonate precipitation that you're seeing from happening. Are you using a doser for soda ash and not dosing manually? (I assume a doser if it's a constant drip.) Also do the kalk and soda ash drip into the sump near each other in a slower flow area? Massive abiotic precipitation is happening for some reason. And with the description of your tank, you shouldn't really need to be dosing alk much at all, as there's little biological uptake. (Unless you have a lot of coralline algae growing, which could maybe do it even without stony corals.)

Also welcome to R2R!

Jason mack · Jan 8, 2019

Welcome to R2R,happy reefing.!!

Donald Wright · Jan 8, 2019

rkpetersen said:
All test results should be confirmed. I'd then raise the magnesium which may keep some of the calcium carbonate precipitation that you're seeing from happening. Are you using a doser for soda ash and not dosing manually? (I assume a doser if it's a constant drip.) Also do the kalk and soda ash drip into the sump near each other in a slower flow area? Massive abiotic precipitation is happening for some reason. And with the description of your tank, you shouldn't really need to be dosing alk much at all, as there's little biological uptake. (Unless you have a lot of coralline algae growing, which could maybe do it even without stony corals.)

Also welcome to R2R!

Kalk is on a doser pump so is the Soda Ash, each dose at opposite ends of the tank in a high flow area. Also they dose at different times. I can increase the Mag a little to see if it will help.

Donald Wright · Jan 8, 2019

reeferfoxx said:
If you aren't reading the measurement incorrectly, i would use a second newer test kit to verify alk levels.

I did buy a new Alk test kit and get the same results.

Donald Wright · Jan 8, 2019

Brew12 said:
Very odd situation. Any chance your Magnesium test may not be accurate? I don't see any reason your alkalinity would precipitate out at the numbers you are using.

Any chance your alkalinity test reads in meq/L instead of dKH?

using the Hanner Checker tester and also Reef liquid test kit, same results. new Mag test kit same results.

Donald Wright · Jan 8, 2019

saltyfilmfolks said:
What Is the ph at ?

#reefsquad
@Randy Holmes-Farley

8.2 during the day, drops to 8.0 at night.

rkpetersen · Jan 9, 2019

Donald Wright said:
Kalk is on a doser pump so is the Soda Ash, each dose at opposite ends of the tank in a high flow area. Also they dose at different times. I can increase the Mag a little to see if it will help.

How often a day for each, and how temporally separated are they?

Also one thing I don't think has been discussed here - Do you have a lot of sand? Abiotic precipitation of calcium carbonate into sand can be extreme. You can tell if your sand bed starts to turn at all hard and rock-like anywhere.

homer1475 · Jan 9, 2019

Stop dosing soda ash and dose baking soda(randy's recipe 2).

I had the same issue, except my sand bed turned to one solid lump also. Once I started dosing recipe 2, my alk issues and precipitate issues went away. You will have to dose more then you currently are, as recipe 2 isn't as concentrated as soda ash.

Donald Wright · Jan 10, 2019

Kalkwasser is on 1.1ml dose pump, is set to 5 hours a day, adds a different times 1 hour at a time, 330 ml a day total. Alkalinity soda ash is set for 8 times a day at 30 min settings. 264 ml of Soda ash a day, all settings are at least 1 hour between either one dosing.
This morning took new readings. Calcium dropped from 420 to 376, Increased Kalkwasser dose another 66 ml a day, dkh was at 6.49 this morning, near what it has been holding at, last measurement was 6.66. Magnesium was at 1320 so have doser pump adding another 60 ml this morning over a hour drip. (Normally don't have to dose Mag) only add when I see a drop. Has been holding at 1360 to 1380 all the time.
Fine Crushed coral is used for bed in tank, no sand. I can still clean the bed just fine it has not hardened up.

I will look at Baking Soda recommendation.