Huge PH Problem

[Bonvivant]

Ok, I am tearing my hair out on this! This is horrible because I have very little to begin with. I had a 50 gallon with 18 gallon sump. PH was between 7.8-8.1 with no problems. I run a CA Reactor. About 3 weeks ago I added a 40 gallon sump and 25 gallon display refugium. I also added a 20 gallon brute trash can as a dsb and cryptic fuge. I used Kolorscape sand for the fuge and sump refugium. I also added about 30-40 pounds of cured live rock. I also used 80 pounds of Tropic Eden Aragasnow for substrate in the display refugium. I have the sum refugium on a reverse daylight schedule.

Previously, I had been using NSW. However, as a result of the larger amount of water needed, I decided to use Red Sea Coral Pro. When I initially mixed an aerated it, the water had a ph of 7.8. I thought this was odd but I used it anyway.

Now for the last 2 weeks I have been battling extremely low PH. I swing from 7.77-7.3. I started using Limewater about a week ago but I have had to manual dose while I wait for a Kalk reactor to come in. I can get the tank up to 8.4 but within a matter of 12 hours its back down to 7.4 or so. I have opened all of the windows and added an air stone from a pump located outside. I have added a pump to the sump to increase surface agitation but it only drove the ph lower! I stopped using the CA reactor about a week ago but there has been no change. I extended a tube for the skimmers air intake outside of the cabinet. Nothing. I am completely frustrated.

My parameters are as follows:
Using salifert Kits:

Ph-7.3-7.-using electronic DA probe (which was recalibrated and tested using RO/DI water)

9.6 DKH
400 Calcium
79.0 Temp
1.26 Salinity
1380 Mag

Is there some contaminent that might be causing the low PH? Do you think there is a cycle? Do you think it may be the Kolorscape sand I used? Any help is greatly appreciated!

 

[ChrisKirkland]

Did you recalibrate your meter with calibration solution? When you test your PH do you draw a cup of water out of the tank and test it?

 

[Bonvivant]

I re calibrated with brand new DA solution. The probe is in the tank and gives a constant reading.

 

[Bonvivant]

Do you think it might be the Red Sea Coral Pro? Should I do a massive water change with NSW? I know others have said water changes don't help but I don't know what to do.

 

[jimmy_beaner]

a "massive" water change may cause a "massive" pH swing, which would be very bad. If you can control it, you should slowly adjust the pH.

 

[Bonvivant]

I am going to install the Kalk reactor with a controller so that it applies Kalk when lower then 8.0 but I am hoping that I don't run into salinity issues. Right now it takes about a gallon of Limewater to get it back to 8.4.

 

[cromedogg33]

I'm curious, you say you took the Ca reactor offline, but you added an airstone, and more surface agitation?

If I'm not mistaken you took the Ca reator offline which lowers your PH, but then you added the airstone and more agitation which also lowers PH. Why would you do this?

I also see your SG at 1.26 which I sure hope is wrong.

 

[Bonvivant]

Sorry 1.026. Surface agitation and more air increase ph.

 

[cromedogg33]

Sorry was thinking when adding vinegar to lower PH to run an airstone as well to help kind of brainfarted there.

You've hopefully read this article:
http://www.reefkeeping.com/issues/2004-09/rhf/index.php

You would probably be best serverd to run Kalk in your ATO so that you can keep your PH elevated constantly.

If there is one thing I've learned from RHF it's that most PH readings come in false. You may have recalibrated your probe but are you certain your probe isn't going bad? I would also verify your Alkalinity.

 

[Bonvivant]

Randy's articles has been a God send! I have read them all. I just ordered a new probe. I am going to re-verify my DKH reading. If it is the same, I am going to raise it to 11 with Randy's Recipe No. 1 for Alkalinity. I think I got a bad batch of Red Sea Coral Pro.

 

[Bonvivant]

Ok, so the update. As I said previously, my PH is very low. goes down to 7.3. My dkh was 9.6. I decided to raise it using the alkalinity portion of Randy's Recipe No. 1 (ie Baked Baking Soda). I dripped about half of the recommended dose when I experienced an abiotic precipitation event. Well, now my PH is reading 7.2 and everything is covered in precipitate. I suspect that my PH probe may be bad so I have ordered another. However, my tank is really suffering. i have several acro colonies either bleaching or showing zero polp extension. I am really frustrated.

 

[cromedogg33]

What are you checking your dkh with? If I've learned anything is don't chase PH unless there is a problem. Were you seeing any ill affects from your "low PH" or were you chasing numbers to get them in check?

 

[Bonvivant]

I am definitely a proponent of your theory but in this case I saw the effects in my tank. Very reduced polyp extension, bleaching ect. I used a Salifert test kit. It is not expired but apparently my DKH must have been higher then measured. What is frustrating is that everything was rock solid and beautiful for over a year. I added the new items to provide more stability and increased food but it might end up destroying everything.

 

[Bonvivant]

If the new probe shows the same PH readings then I am seriously considering replacing all of the water in 3 or 4 massive water changes.

 

[Tbduval]

I find it hard to believe your PH is really that low. I could see 7.6 on the low side but 7.2 I can't believe. Let's slow down some. Changing the all the water in 3 or 4 WC's can cause its own issues. You are testing with a probe, which is good. You are using the 7 & 10 fluids to calibrate it right? Is your PH going up during when the lights are on?

It sounds to me you may have excessive CO2 in the tank. You should really do the outside test and see if raises will outside. I would unplug everything from your tank except for the main pump. See if the PH changes, if not unplug the main pump, see what PH does. Let's make sure there is no interference going on with the probe. Let us know.

 

[Bonvivant]

I'm just frustrated. Yes I calibrated the probe with the DA 7 and 10 packets that were newly purchased. The ph does go up in the day to about 7.6-7.77 and then drops at night. I never thought that the probe might be experiencing interference. I moved it to the display tank. However, the probe wire does cross some electrical wires. The problem is that I observe changes in the tank. When PH is at the low range polyp extension is zero. When the PH is raised everything perks up. Also, the PH drops slowly over about a 12 hour period. I have run an air pump from outside to introduce fresh air. I have also increased agitation in the sump and moved the skimmers air intake further from the cabinet.

 

[Tbduval]

Not sure if you are experiencing interference. Just something to rule out since it is an electrical equipment. Are you having any hair algae or other algae issues?

 

[Bonvivant]

Not really. Have had some cyano growing. Why?

 

[Randy Holmes-Farley]

Is there some contaminent that might be causing the low PH?

I don't believe the pH 7.3 is real.

No, there is nothing impacting pH in seawater aside from alkalinity and CO2 level. Together those determine the pH exactly.

So if pH is low and alkalinity is OK, then CO2 levels are high.

Try aerating a cup of tank water outside for an hour. The pH should rise a lot. When it does, that confirms it is CO2. If not, then there is a measurement problem of some sort.

This has more:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

 

[cromedogg33]

I am definitely a proponent of your theory but in this case I saw the effects in my tank. Very reduced polyp extension, bleaching ect. I used a Salifert test kit. It is not expired but apparently my DKH must have been higher then measured. What is frustrating is that everything was rock solid and beautiful for over a year. I added the new items to provide more stability and increased food but it might end up destroying everything.

This is what concerns me... "the new items"

Have you contemplated turning these completely off to see if you introduced something? For every action there is and equal but opposite reaction :hmm5:

You say you just added these and now you are having the problems....

That would be my starting point.