Low ALK, high PH?

[dburt520]

Quick background:

Tank is about 280g total water volume and is relatively new - three months old and have absolutely no corals in it. Sand, dry rock, fish, CUC and fuge is online running chaeto. Have absolutely no visible traces of coraline in the tank. I am using Tropic Marin Pro Reef salt.

My issue: I can't seem to get my ALk to "hold" or stabilize. It consumes roughly 2.0 DKH a day. I have checked all of my pumps, powerheads, and heaters and do not see any trace of precipitation. The tank is crystal clear and all other elements are stable and where I would like to keep them long term.

CA 413
MG 1330
PO4 .04-.06 daily with a Hannah
NO3 somewhere between 2-5.
PH 8.36 - 8.44 (the last 24 hour low/high on my apex. I calibrated the PH probe two days ago to verify my PH probe was accurate).

I was dosing about 20ML a day for a bit as my ALK was dropping about 2.0 DKH a day - I did not want my ALK/CA/PH to get to far out of balance, so I was trying to hold it there. My 20 ML per day just wasn't cutting it and eventually turned into around 160 ML a day (this was short lived). I have since stopped dosing anything for now (about two weeks ago) and have just been letting things run. Alk is currently sitting at 6.58 (Trident and Hanna actually match, or are very very close). My ALK will hover right around 6.5-6.6 with out dosing anything, but if I try to elevate it, it drops right back down. Same thing occurs after a water change.

Any idea what would cause my alk consumption with nothing in the tank, and no visual evidence of precipitation?

Thank you

 

[lapin]

maybe the 8th post in this thread?

Massive Alkalinity Consumption. Please Help!

I have a 40 gallon breeder tank with a mix of coral: sps, lps, and some zoas. None of them are huge colonies. About a dozen pieces in total. Recently, my alkalinity consumption has skyrocketed. Tonight, I dosed up to 9.5 dkh, and within 4 hours it was back down to 8.6, even with my automatic dose...

www.nano-reef.com

and other reading

How Alkalinity Affects Nitrification | California Water Environment Association

Use alkalinity profiling in wastewater operations to control biological activity and optimize process control The Water Environment Federation’s new Operations Challenge laboratory event will determine alkalinity needs to facilitate nitrification. Operators will evaluate alkalinity and ammonia...

www.cwea.org

 

[Randy Holmes-Farley]

FWIW, the pH is fine.

 

[dburt520]

maybe the 8th post in this thread?

Massive Alkalinity Consumption. Please Help!

I have a 40 gallon breeder tank with a mix of coral: sps, lps, and some zoas. None of them are huge colonies. About a dozen pieces in total. Recently, my alkalinity consumption has skyrocketed. Tonight, I dosed up to 9.5 dkh, and within 4 hours it was back down to 8.6, even with my automatic dose...

www.nano-reef.com

and other reading

How Alkalinity Affects Nitrification | California Water Environment Association

Use alkalinity profiling in wastewater operations to control biological activity and optimize process control The Water Environment Federation’s new Operations Challenge laboratory event will determine alkalinity needs to facilitate nitrification. Operators will evaluate alkalinity and ammonia...

www.cwea.org

I've read alot about nitrification consuming alk, but at what point does it steady out, or at what alk consumption number per day do I start to consider it may be something else?

I haven't put any coral at all in the tank yet as there is no way I could keep the alk stable or corals happy.

 

[dburt520]

The PH is ideal for where I wish it to be, but with the alk being 6.5, won't the PH come up naturally as the alk comes up?

 

[Randy Holmes-Farley]

I've read alot about nitrification consuming alk, but at what point does it steady out, or at what alk consumption number per day do I start to consider it may be something else?

I haven't put any coral at all in the tank yet as there is no way I could keep the alk stable or corals happy.

When nitrate is steady, the alk effect is zero.

6.5 to 7 dKH is perfectly fine for corals. Hard corals may grow a bit more slowly than at higher alk, but that alk level approximates their natural environment.

The reason it is dropping and stopping is likely abiotic precipitation. It declines as alk declines, and slows to a stop.

 

[Randy Holmes-Farley]

Quick background:

Tank is about 280g total water volume and is relatively new - three months old and have absolutely no corals in it. Sand, dry rock, fish, CUC and fuge is online running chaeto. Have absolutely no visible traces of coraline in the tank. I am using Tropic Marin Pro Reef salt.

My issue: I can't seem to get my ALk to "hold" or stabilize. It consumes roughly 2.0 DKH a day. I have checked all of my pumps, powerheads, and heaters and do not see any trace of precipitation. The tank is crystal clear and all other elements are stable and where I would like to keep them long term.

CA 413
MG 1330
PO4 .04-.06 daily with a Hannah
NO3 somewhere between 2-5.
PH 8.36 - 8.44 (the last 24 hour low/high on my apex. I calibrated the PH probe two days ago to verify my PH probe was accurate).

I was dosing about 20ML a day for a bit as my ALK was dropping about 2.0 DKH a day - I did not want my ALK/CA/PH to get to far out of balance, so I was trying to hold it there. My 20 ML per day just wasn't cutting it and eventually turned into around 160 ML a day (this was short lived). I have since stopped dosing anything for now (about two weeks ago) and have just been letting things run. Alk is currently sitting at 6.58 (Trident and Hanna actually match, or are very very close). My ALK will hover right around 6.5-6.6 with out dosing anything, but if I try to elevate it, it drops right back down. Same thing occurs after a water change.

Any idea what would cause my alk consumption with nothing in the tank, and no visual evidence of precipitation?

Thank you

What exactly are you dosing?

I think you may have miscalculated.

If my DIY Recipe 1 (like BRS soda ash recipe), 20 mL is only 0.1 dKh per day, and 160 mL is only 0.8 dKH per day.

I'd suggest switching to baking soda for alk supplementation to let the pH decline a little and cause less precipitation.

I'd also suggest double checking the alk measuring method. The pH should not be that high for 6 .5 dKH without dosing.

It is unimportant if the pH measurement is off a bit, but if the alk is really 8 dKH right now, that's a bigger concern.

 

[dburt520]

What exactly are you dosing?

I think you may have miscalculated.

If my DIY Recipe 1 (like BRS soda ash recipe), 20 mL is only 0.1 dKh per day, and 160 mL is only 0.8 dKH per day.

I'd suggest switching to baking soda for alk supplementation to let the pH decline a little and cause less precipitation.

I'd also suggest double checking the alk measuring method. The pH should not be that high for 6 .5 dKH without dosing.

It is unimportant if the pH measurement is off a bit, but if the alk is really 8 dKH right now, that's a bigger concern.

Dosing BRS Soda Ash, which explains the higher PH and lower ALK - the soda ash will raise the PH but should the PH drop as the ALK is consumed or precipitated off?

Measuring ALk with a Hannah as well as a Trident, both tests are within .02 of each other every time.

All other elements that I can test appear to remain stable, nitrate, phosphate calcium and magnesium.

Traditionally in my house I have struggled with low PH - to see PH numbers that are in the "ideal" range is quite a nice surprise, hopefully I can get them to hold long term.

 

[dburt520]

200ML per day was shy of what was reccomended on the BRS calculator for a 1.5 DKH per day - 289.2 ml was the reccomended, but my brain told me something was wrong somewhere if I was dosing 200+ ML in a tank with absolutely no corals.

 

[Randy Holmes-Farley]

200ML per day was shy of what was reccomended on the BRS calculator for a 1.5 DKH per day - 289.2 ml was the reccomended, but my brain told me something was wrong somewhere if I was dosing 200+ ML in a tank with absolutely no corals.

Can you describe how much soda ash to what volume of fresh water? Some folks buying ingredients from BRS get my two recipes confused (BRS sells ingredients for both, and they have different potencies).

 

[dburt520]

I am using one of these.

Pharma Soda Ash 1 Gallon Mix (Single Use)

Ultra-pure Grade Soda Ash for 2-part dosing in your reef tank! Bulk Reef Supply 2-part additives are the perfect solution to replenish the intake of calcium and alkalinity coral consumes when it grows. Using only pharmaceutical grade ingredients allows you to keep a cleaner reef with fewer...

www.bulkreefsupply.com

Mixed in one of these with 1 gallon of RODI:

Space Saver Jug - Thin 4 Liter (1.05 Gallon)

Why does BRS recommend this? Thin Space Saver Jugs are great for storing 2 part solutions in tight spaces. Each jug can hold roughly 1 gallon and takes up only 2 ½ inches in width. A great slimmer alternative to the standard Mr. Chili mixing jugs. Dimensions: 9-1/4"L x 2-1/2"W x 14 3/4"H...

www.bulkreefsupply.com

 

[dburt520]

And if I use their dosing calculator, selecting Alkalinity, then Liquid Soda Ash, then New Pharma Pouch, input my tank volume as 270G (which does appear to be pretty accurate as I can measure the desired reading shortly after dosing), then set my current DKH to 6.5, desired to 8.0 it tells me to dose 289.2 ml.

 

[Randy Holmes-Farley]

And if I use their dosing calculator, selecting Alkalinity, then Liquid Soda Ash, then New Pharma Pouch, input my tank volume as 270G (which does appear to be pretty accurate as I can measure the desired reading shortly after dosing), then set my current DKH to 6.5, desired to 8.0 it tells me to dose 289.2 ml.

Regardless of what you are dosing, that is not a good jump to try to make at once. Too big.

try dosing just 0.5 dKH per day, and preferably use baking soda. You likely have plenty in your kitchen already.

There is zero reason to target alkalinity above 6.5-7dKH when there is nothing to use it.

 

[dburt520]

I mixed up 1 gallon of your #2 recipe Alkalinity using Arm and Hammer baking soda and RODI - can you steer me in the right direction for an accurate dosing calculator?

 

[gtguy256]

Make sure to check your sand. I was dosing without much coral load and my sand started to turn into rock. Just something to be aware of

 

[dburt520]

I'd prefer to not dose anything in an empty tank to be honest, but my ALK will plummet and based on past experiences once the ALK/CA drift so far out of wack it becomes quite the chore to bring them back together.

I wish I could figure out what is consuming the ALK - maybe it is nitrification, but 2.0 DKH a day just seems like alot for a coral less tank, a corline free tank, and no new inhabitant additions in month.

 

[dburt520]

I actually found the calculator - the one I previously had saved was no longer working!

After I input all of my numbers it is reccomending 192.8ML to raise my current 6.0 ALK to 6.5 - does that sound accurate? Again, total.water volume is 270G.

 

[homer1475]

I like this calc. For plain baking soda, use randys recipe 2.

Reef Chemistry Calculator

@ 270G and 6.5 to 7.0 is 192.8ml. Yes that calculation is correct. I would agree that seems like a ton to be adding to an empty tank. Have you checked your sandbed to se if it's hardening in areas at all?

 

[dburt520]

It does not appear to be hardening anywhere that I can see.

 

[dburt520]

Wanted to bring this one back to life.

I turned off all dosers for the past 10 days - haven't dose anything at all.

I've done two large'ish water changes (20 gallons each), and am still seeing my ALk drop a good bit.

Monday - 4:00 PM, All was 5.71
Today (Thursday) - 8:00 AM All was 5.35.

My goal here is obviously get my ALK up into the 8 range and start moving my corals over. Should I start dosing the tank again to bring the levels up? If so, what recipe (I have RHF #2 with Baking Soda and BRS Soda Ash made up and available). How slowly should I look at bringing the number up?

My PH, Mag, CA levels are all "good", and stable.
PH - 8.15 - 8.30 swing during a 24 hour period
CA - steady at 440
MAG - Steady at 1360

Thanks