PH too high even after water change - can't get under control - Page 2

ryanpal · 02/24/2018, 10:11 AM

wow it looks like the php probe was way off. after recalibrating it now shows 8.13. it was off by roughly .5

thank you for all the assistance, its much appreciated as always

HBtank · 02/24/2018, 10:18 AM

Quote:

Originally Posted by ryanpal

wow it looks like the php probe was way off. after recalibrating it now shows 8.13. it was off by roughly .5

thank you for all the assistance, its much appreciated as always

Yeah your description really felt like that. Just have a pH test kit around and verify once a month or so with probes, and calibrate a small needed.

Sk8r · 02/24/2018, 10:43 AM

In general, ph is a moving target in reef systems. For a good picture of the water conditions, be sure and test your alkalinity at least weekly, write down the number, and track it through the year. I keep a balance of 8.3 alk, 420 calcium, 1350 magnesium, and use kalk in the topoff water to hold it steady. Alk is related to ph, but is steadier; and it is often at fault when things go wonky.

slief · 02/24/2018, 01:59 PM

Quote:

Originally Posted by ryanpal

a few days ago i tested alk and it was extremely low: 3.7 and calcium was 350. i didnt understand why it was so low and i found out it was because the coding for the apex is set to stop dosing alk if ph raised above 8.4. i decided to raise the threshold to 8.5 so i could raise alk but the ph rose with it as well.

i'm measuring ph with the apex probe

And what are you dosing for Alk? Soda ash (sodium carbonate) tends to raise pH and is only recommended for tanks with lower pH. Baking soda (sodium bicarbonate) is used with tanks that already have a high pH. If your pH readings are accurate and you want to maintain slightly lower pH levels, switch to Sodium Bicarbonate for your Alk part assuming you are using sodium carbonate.

ryanpal · 02/26/2018, 11:05 AM

uh oh. i think i posted back too fast. my ph readings are 8.6 again. perhaps the ph dropped from dosing with baking soda instead of soda as recommended in this post? after testing the ph probe i switched back to soda ash.

the other part to this is that i tested alk after seeing the huge spike in ph and noticed the alk was extremely high 14.7. i guess did something wrong with the dosing calculator with the baking soda.

slief · 02/26/2018, 12:53 PM

Quote:

Originally Posted by ryanpal

uh oh. i think i posted back too fast. my ph readings are 8.6 again. perhaps the ph dropped from dosing with baking soda instead of soda as recommended in this post? after testing the ph probe i switched back to soda ash.

the other part to this is that i tested alk after seeing the huge spike in ph and noticed the alk was extremely high 14.7. i guess did something wrong with the dosing calculator with the baking soda.

As I said, Soda Ash WILL raise your pH. Baking Soda is the preferred solution for Alk in higher pH systems as it doesn't impact pH like Soda Ash does. You really should be using baking soda if your pH is anywhere near as high as you think it is and I would expect your pH to drop when using baking soda. You should also go slowly with your dosing and use half doses until you get a feel for the increase in Alk when you switch from one to the other.

Bent · 02/26/2018, 02:05 PM

Raises hand*

Since class is in session here I have a question. I think I already know the answer.

Is it possible to maintain a rock solid pH while your alk is slowly depleting, or do they go hand in hand?

Meaning, is it possible to drop from an alk of 8 to 6 with no associated drop in pH?

02/24/2018, 10:43 AM	#28
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	In general, ph is a moving target in reef systems. For a good picture of the water conditions, be sure and test your alkalinity at least weekly, write down the number, and track it through the year. I keep a balance of 8.3 alk, 420 calcium, 1350 magnesium, and use kalk in the topoff water to hold it steady. Alk is related to ph, but is steadier; and it is often at fault when things go wonky. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

02/26/2018, 02:05 PM	#32
Bent I got nothin' Join Date: Nov 2004 Location: The anals Posts: 6,420	Raises hand* Since class is in session here I have a question. I think I already know the answer. Is it possible to maintain a rock solid pH while your alk is slowly depleting, or do they go hand in hand? Meaning, is it possible to drop from an alk of 8 to 6 with no associated drop in pH? __________________ Quitters never lose. [QUOTE=CStrickland]Who gets mad at a starfish?[/QUOTE] Current Tank Info: 75g DT, 30G refugium, 10g chaeto tank, 50g stock tank basement sump

02/24/2018, 10:11 AM	#26
ryanpal Registered Member Join Date: Jul 2006 Location: New Jersey Posts: 756	wow it looks like the php probe was way off. after recalibrating it now shows 8.13. it was off by roughly .5 thank you for all the assistance, its much appreciated as always

02/26/2018, 11:05 AM	#30
ryanpal Registered Member Join Date: Jul 2006 Location: New Jersey Posts: 756	uh oh. i think i posted back too fast. my ph readings are 8.6 again. perhaps the ph dropped from dosing with baking soda instead of soda as recommended in this post? after testing the ph probe i switched back to soda ash. the other part to this is that i tested alk after seeing the huge spike in ph and noticed the alk was extremely high 14.7. i guess did something wrong with the dosing calculator with the baking soda.