Ph and Alk

fishsince3 · 07/17/2019, 08:28 AM

Hey everyone. A rather sudden issue I’ve run into in the last week. My tank has suddenly had a constant drop in ph, was running 8.2/3 and is now consistently coming back at 7.7/8. This is coupled with a constant depletion of alk, it was running up near 12 now is coming back around 7/8. Both of these lead me to believe calcium would be low too but calcium is near 400-430 consistently. SG is constantly at 1.025/026. Had my LFS run magnesium and that was in line they said as well.

After dosing the next day both levels are immediately back down. None of the corals are looking happy though the other inverts all seem good.

Husbandry hasn’t changed in the last 5-6 months, 30% water change every Sunday, daily glass wipe down with a mag float, clean all pumps every other week, feeding once a day in the AM.

Please help.

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Vinny Kreyling · 07/17/2019, 08:34 AM

All windows closed with the AC on I would guess.
Could just be more CO2 in the air.
If you get a cool day open the windows & see what happens.

fishsince3 · 07/17/2019, 08:43 AM

Quote:

Originally Posted by Vinny Kreyling

All windows closed with the AC on I would guess.
Could just be more CO2 in the air.
If you get a cool day open the windows & see what happens.

I read that a few other places. Anyway to kind of simulate it? (in Chicago no cool days coming in any time soon)

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Uncle99 · 07/17/2019, 10:08 AM

MG must be in the 1200-1360 level, otherwise Alk ions are just going to attach to CA ions......test MG and ensure your on the higher end of that range, then slowly bring up Alk, wait 24 hours, retest PH. 7,8 is not a bad number
If you have a skimmer and can pull outside air into the mix that will help
Or CO2 scrubber but that’s kinda expensive

bertoni · 07/18/2019, 08:46 PM

I agree that pH at 7.8 is normal for a tank with the windows shut. Lots of Tanks of the Month ran at that level. The drop in alkalinity probably is simply due to coral growth. The ratio of consumption is 2.8 dKH per 20 ppm of calcium, so calcium consumption is hard to measure.

bnumair · 07/18/2019, 09:56 PM

What instrument are you using to measure pH?
Also dosing alkalinity solution will bring up alk but will have a temporary effect on pH. Although if pH of 7.8 is correct then it's not bad. It acceptable.
Alk could be low due to consumption. A healthy reef tank can consume 2-4 dkh per day. Very normal.
Are you using denitrator?

Your corals are not happy because of fluctuating alk and pH.
I wouldn't chase pH but try to keep a constant slow dose of alk solution so the alk remains stable throughout the day. Consistency is the key rather than a number.

Can you ask the lfs to give us the mag result? What was the final number they concluded?

JustAClownFish · 07/19/2019, 08:16 AM

Alk of 12 is way too high anyway. Ph of 7.8-8.2 is fine. Stop stressing. Dose alk to keep it at NSW levels of around 7-8 dkh. If you want to do the chasing number games dose kalkwasser. It’ll bring your ph up.

hkgar · 07/19/2019, 12:54 PM

What is your Mag level?
I know it has been asked but it is an important measurement that is often overlooked.

07/17/2019, 08:28 AM	#1
fishsince3 Registered Member Join Date: Mar 2009 Location: Chicago Posts: 119	Ph and Alk Hey everyone. A rather sudden issue I’ve run into in the last week. My tank has suddenly had a constant drop in ph, was running 8.2/3 and is now consistently coming back at 7.7/8. This is coupled with a constant depletion of alk, it was running up near 12 now is coming back around 7/8. Both of these lead me to believe calcium would be low too but calcium is near 400-430 consistently. SG is constantly at 1.025/026. Had my LFS run magnesium and that was in line they said as well. After dosing the next day both levels are immediately back down. None of the corals are looking happy though the other inverts all seem good. Husbandry hasn’t changed in the last 5-6 months, 30% water change every Sunday, daily glass wipe down with a mag float, clean all pumps every other week, feeding once a day in the AM. Please help. Sent from my iPhone using Tapatalk __________________ -Mike If god didn't want us to eat animals - why did he make them so delicious? Current Tank Info: 14g biocube, AI LED, LPS/SPS mix

07/17/2019, 08:34 AM	#2
Vinny Kreyling Registered Member Join Date: Nov 2002 Location: Miller Place, NY Posts: 7,206	All windows closed with the AC on I would guess. Could just be more CO2 in the air. If you get a cool day open the windows & see what happens. __________________ 250 gallon mixed reef, 2 Reefbreeder's Photon V 2, Deepwater BLDC 12, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.

07/18/2019, 08:46 PM	#5
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I agree that pH at 7.8 is normal for a tank with the windows shut. Lots of Tanks of the Month ran at that level. The drop in alkalinity probably is simply due to coral growth. The ratio of consumption is 2.8 dKH per 20 ppm of calcium, so calcium consumption is hard to measure. __________________ Jonathan Bertoni

07/18/2019, 09:56 PM	#6
bnumair Dr. Reef at ur service Join Date: May 2009 Location: Tulsa, Ok, USA Posts: 7,751 Blog Entries: 15	What instrument are you using to measure pH? Also dosing alkalinity solution will bring up alk but will have a temporary effect on pH. Although if pH of 7.8 is correct then it's not bad. It acceptable. Alk could be low due to consumption. A healthy reef tank can consume 2-4 dkh per day. Very normal. Are you using denitrator? Your corals are not happy because of fluctuating alk and pH. I wouldn't chase pH but try to keep a constant slow dose of alk solution so the alk remains stable throughout the day. Consistency is the key rather than a number. Can you ask the lfs to give us the mag result? What was the final number they concluded? __________________ Water Quality: NO3 0,Phos 0,Cal 440,Alk 7.5,Mag 1300 "Reef Fast, You Crash, Reef Slow, You Pass" Mike's Reef 3:16 Current Tank Info: 350g DT,95g sump, 50g Frag tank, 4800gph return 4x Sea swirls. 6x AI Vega Color. 200# Pukani rock, dual recirculating skimmer, Biopellet, GFO Carbon rx's, Cal rx. Closed loop. 1.5hp chiller, genesis renew. Apex & RKE Last edited by bnumair; 07/18/2019 at 10:01 PM.

07/19/2019, 12:54 PM	#8
hkgar Registered Member Join Date: Oct 2002 Location: Dewitt MI Posts: 5,051	What is your Mag level? I know it has been asked but it is an important measurement that is often overlooked. __________________ Gary 180 gallon, 40 gallon sump, 3 250 W MH + 4 80W ATI T5's, MTC MVX 36 Skimmer, Apex controller Aquamaxx T-3 CaRx Current Tank Info: A 2 Barred Rabbitfish, Red Head Salon, Yellow/Purple, McMaster Fairy, Possum, 2 Leopard Wrasses, Kole, & Atlantic Blue Tangs, 2 Percula Clown, 3 PJ and 1 Banggai Cardinalfish , Swallowtail, Bellus and Coral Beauty Angels

07/17/2019, 10:08 AM	#4
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	MG must be in the 1200-1360 level, otherwise Alk ions are just going to attach to CA ions......test MG and ensure your on the higher end of that range, then slowly bring up Alk, wait 24 hours, retest PH. 7,8 is not a bad number If you have a skimmer and can pull outside air into the mix that will help Or CO2 scrubber but that’s kinda expensive

07/19/2019, 08:16 AM	#7
JustAClownFish Registered Member Join Date: Oct 2017 Location: California Posts: 226	Alk of 12 is way too high anyway. Ph of 7.8-8.2 is fine. Stop stressing. Dose alk to keep it at NSW levels of around 7-8 dkh. If you want to do the chasing number games dose kalkwasser. It’ll bring your ph up.