Always low PH and what to do???

[Markerum]

I have a 60 gallon with 29 gallon refugium. It is a mixed reef and I dose 2 part every day.
My alk is 8.5
calcium 390
Nitrates 0
Nitrites 0
salinity 1.025
ammonia 0
Phos 0
but my ph is the lowest ever at 7.6
Why does it always drop and how should I safely raise it. I do have a ph buffer and started adding some last night. It says it will raise to 8.3 with repeated use.
Any advice on this situation would be great. The tank is a year and a half old and has a sand bed of three inches. I did not see this being a problem but it is just getting worse and I do not know ow to handle it.

[NCguy]

What is the PH of your TO water? I have a well and after it comes out of my RO/DI my PH is only 6 so i really have to buffer mine.
Also do you run your fuge on a reverse light cycle than your main tank? This helps with the PH swing.

[lvpd186]

Read through this , maybe you will find your answer there.

[Lunchbucket]

Most likely this time of year it is due to having the whole house closed up tight. Open a window to get some fresh air to the tank or put your skimmers air hose out a window to constantly suck fresh air.

Kalk, Reverse light cycle fuge, etc

How are you testing your pH?

Lunchbucket

[RichT]

Be very careful of the PH buffer. It raises you Alk to increase PH. I did the same, dosing PH buffer, and unknowingly raised my Alk off the chart. Killed a bunch of beautiful corals. Needless to say, I don't use PH buffer any longer. Most of the "experts" advise against it as well.
Good Luck, there is a plethora of info in the Chemistry Forum to help you out.

[Markerum]

Ro/DI water is used as top off. Never checked the PH of that, will do. I have a reverse light cycle with my refugium.
I was worried about my alk using the buffer. So how else can PH be raised safely???

[RichT]

Kalk dripping helps a lot. But as usual, it's better to find the source of the problem instead of treating the symptom. Review the Chemistry Forum. There are many articles in Reef Keeping magazine that will also help you trouble shoot your problem.

[NCguy]

Not to steal your thread but i dose 2 part everyday as well. I had the same problem as you after the tank was about a year old until i started Buffering my TO water. It did however raise my Alk so i started using less Alk of my 2 part dosing. I've been doing this for at least a year without any problems but i wonder am i going about this kinda backwards or something.?? i've always thought if it isn't broke don't fix it but i kinda hate to be doing something wrong chemistry wise.

[Markerum]

interseting, but I am not sure, don't the two parts have to bond together so need to be equal. This is well above my chemistry level though.

[Randy Holmes-Farley]

Ro/DI water is used as top off. Never checked the PH of that, will do.

Don't bother. The pH of top off water is NEVER the cause of low pH, regardless of what value you get for it.

This article has more:

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

and

The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH
http://reefkeeping.com/issues/2007-05/rhf/index.php

from this one:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm

Final Effluent pH

Aside from the issues discussed above concerning the effluent’s pH when the DI resin becomes depleted, the final pH coming out of an RO/DI system should not significantly concern reef aquarists. Many aquarists with low pH problems have asked, for example, if their aquarium’s low pH may be caused by their replacing evaporated water with RO/DI water that they measure to have a pH below 7. In short, the answer is no, this is not a cause of low pH nor is it something to be generally concerned about, for the following reasons:

1. The pH of totally pure water is around 7 (with the exact value depending on temperature). As carbon dioxide from the atmosphere enters the water, the pH drops into the 6’s and even into the 5’s, depending on the amount of CO2. At saturation with the level of CO2 in normal (outside) air, the pH would be about 5.66. Indoor air often has even more CO2, and the pH can drop a bit lower, into the 5’s. Consequently, the pH of highly purified water coming from an RO/DI unit is expected to be in the pH 5-7 range.

2. The pH of highly purified water is not accurately measured by test kits, or by pH meters. There are several different reasons for this, including the fact that highly purified water has very little buffering capacity, so its pH is easily changed. Even the acidity or basicity of a pH test kit’s indicator dye is enough to alter pure water’s measured pH. As for pH meters, the probes themselves do not function well in the very low ionic strength of pure freshwater, and trace impurities on them can swing the pH around quite a bit.

3. The pH of the combination of two solutions does not necessarily reflect the average (not even a weighted average) of their two pH values. The final pH of a mixture may actually not even be between the pH’s of the two solutions when combined. Consequently, adding pH 7 pure water to pH 8.2 seawater may not even result in a pH below 8.2, but rather might be higher than 8.2 (for complex reasons relating to the acidity of bicarbonate in seawater vs. freshwater).

[vessxpress1]

How are you checking your pH? Have you verified with other kits or a properly calibrated pH monitor? Be careful assuming it really is that low first off.

If it is, if you can dose a little kalk in the top off water, it should fix it. Kalk is extremely potent so be careful.

pH buffer is also extremely potent. If you mix up a gallon of new saltwater and the pH is a little low, it takes barely even a pinch of buffer to raise the pH to 8.3 or higher. I only add it to newly mixed saltwater to assure that the pH is up there before adding it to the tank. It isn't a permanent fix for low pH by any means.

Try using a two part also. I use B-ionic every morning and it keeps the alk and Ca up nicely along with kalk coming from my ATO.

[Cultivatedcoral]

Hi Markerum,

I agree with lunch bucket. Being in Florida as well, these new homes are built pretty much air tight. I have had the same problem in my own home since there is no fresh air coming in.

Since it's winter time you should be able to open a window or slider and left fresh air in every day for a few hours. I know it's hard in the summer opening windows because the heat is just to much so I usually wait until night time in the summer to open a window for a few hours.

Good luck.

Nick

[Markerum]

Windows are open and it is a new home here in florida so lets see what happens. I test with a test kit. It may not be that accurate but my reading is still lower than what it use to be. It has always been low but it is just getting lower

[Randy Holmes-Farley]

The article I posted gives an aeration test you can do to diagnose the source of the excess CO2 (home air or just trapped in the tank).

[Markerum]

What to do if it is low aeration. I will test but I will be surprised. I have a waterfall in my refugium and alot of water movment at the top of my tank. I have reduced my canopy fans as the temperature has been cool in the house, could that effect?

[Randy Holmes-Farley]

If aeration is high (skimmers help a lot), then if the pH is really low, more outside air or limewater are the best bets. Fans won't impact CO2 in the tank much.

[Pmolan]

Add some plants in your living room. I have too many and my pH will hit 8.7 if I dont keep it in check.