PDA

View Full Version : ph keeps going down !!!!!!


becki boggs
09/06/2006, 07:09 PM
i dont know why the ph keeps going down ,cal,nitrate nitrite amonium are 0.

LittlePuff
09/07/2006, 09:04 PM
Increase surface agitation.

abugs1985
09/07/2006, 09:07 PM
if you have powerheads in your tank connect an air tube to one (usually they come with the tubes) and get some oxygen in the water.

AQUA DAVE
09/07/2006, 09:13 PM
Do you have a calcium reactor running on the system? If you do and you are controlling it by monitoring your ph in your sump It could be your reactor pulling the ph down. You should always measure the ph from the reactor if using a calcium reactor because your controller will constantly leave your CO2 running and dissolve your calcium quickly, which brings down ph also. Some people use a calc reactor to remedy this as it does the opposite and raises ph.

drummereef
09/07/2006, 09:34 PM
What's your alkalinity? Have you tried opening some windows. Could be a Co2 buildup in your house.

dbrody01
09/07/2006, 10:28 PM
Try baking some baking soda for an hour at 300F then dosing that, in small increments so as not to raise pH too fast.

sir_dudeguy
09/07/2006, 10:35 PM
do you have an open or closed top? if you've got a glass top or one of those plastic lids that doesnt allow for any gass exchange (and imo the 1 or 2 inch gap in the back isnt gonna cut it), then your pH will drop. You need good surface agitation to get the gas to exchange, but if you dont have anywhere for the gas to go in and out of the system...well..you're not really exchanging much.

timespinner
09/07/2006, 10:58 PM
Try: http://reefkeeping.com/issues/2004-09/rhf/index.htm

drummereef
09/08/2006, 12:45 AM
I think we need to get some accurate testing from Becki. What are all your parameters including alk and calcium?

jeffbrig
09/08/2006, 09:57 AM
I would guess depleted alkalinity, and high indoor CO2.

Do NOT sprinkle baked baking soda powder directly to your tank. It can shift the pH quickly, even with very small amounts. Not to mention, you should never blindly dose an alkalinity supplment to "correct" pH. Measure alkalinity, calculate how much you need to correct the low alkalinity and go from there. Mix the proper amount with RO/DI water, and add in small amounts over time, while monitoring pH. Never let pH move more than .2 during any single addition.

becki boggs
09/08/2006, 08:17 PM
my calcium is at 480
nitrite-0
ammonia-0
nitrate-0
i have 3 maxi jet 900 , 1 maxi jet 1200 and a sweeper
would changing the power jets around do this? the ph went down on 9/6/06 and today they were fine
i have a covered tank with air holes in top ,but this summer in texas heat i have one one part of the top slightly up with a fan cooling my lights.
dont have a calcium reacter.

NaH2Ofreak
09/08/2006, 08:57 PM
If your calclium is indeed that high, then your alkalinity would be real low. This is most likely why you are seeing low pH. Do you have an alkalinity test kit? You will probably need to dose an alkalinity additive. This will also bring your Calcium level down a little also, which couldnt hurt.

Dennis

drummereef
09/08/2006, 10:27 PM
Still need to get how low the pH is actually going. Can you tell us the pH at the end of the light cycle and first thing before light go on? And an accurate alkalinity test is a must. I wouldn't start dosing until all testing is certain. Yes, the calcium is a little on the high side, but the other tests are needed to determine exactly what's going on.

mg426
09/08/2006, 10:41 PM
Have you tried the aeration test??

navajo
09/09/2006, 12:20 AM
I had a similar problem a while back. I wasn't thinking and was topping off with straight RO water automatically. Really lowered the PH and chewed up some Alk.

Good luck with this!

becki boggs
09/09/2006, 07:26 PM
i also top off with sraight RO water , what shold i be topping off with?

becki boggs
09/09/2006, 07:26 PM
i also top off with sraight RO water , what should i be topping off with?

navajo
09/09/2006, 09:08 PM
Well, since RO water has a very low pH, You (and I) should be aerating the RO water at the least and possibly buffering it before using it as top off.

What I have done is run my Ro water into a seperate holding tank and use this as my Kalk mixing tank before using it as top off. Bumped my pH back up to a solid ~8.3

ufchristyb
09/09/2006, 09:58 PM
Topping off with RO water actually has no impact on your pH. If you read the dull articles in the reef chemistry forum :D, pH represents a simple ratio of H+ ions to OH- ions. Since RO(/DI) is pure, it has little or no ions in it. Overall, you can think of it as being completely neutral, but the pH of RO water is pretty much impossible to measure. Because the number of ions present, small differences can blow the pH high or low. However, when mixed with saltwater in the tank, the huge number of ions present in the saltwater completely overwhelm any contribution from the RO water.

Buffering topoff water for alkalinity alone can be a very bad thing to do. If you add a true alkalinity buffer (baking or washing soda), you will upset the balance between Calcium and alkalinity over time.

Kalkwasser is fine, since it's a balanced additive (replacing both Ca and Alk in the proper ratio). However, if you already have a scheme in place to replenish/maintain Ca and Alkalinity, you will have absolutely no problem topping off with straight RO.

navajo
09/09/2006, 10:20 PM
<a href=showthread.php?s=&postid=8113502#post8113502 target=_blank>Originally posted</a> by ufchristyb
Topping off with RO water actually has no impact on your pH.


I respectfully disagree. I was topping off with RO water for a few months when I first started and couldn't get my pH above about 7.8 ( I don't use the ph up or down additives. Try to stay away from most additives out there).

I then emailed wetwebmedia and asked them what was going on and was told to at least aerate the RO water before use and it has been smooth sailing ever since (it was a while after that I started with the Kalk mixing).

If you're interested in what they have to say on the matter:

http://www.wetwebmedia.com/rofaqs.htm

(MODS, if it is not OK to place that link here, I apologize and please remove it.)

drummereef
09/09/2006, 11:06 PM
Yes, you should be aerating your RO water, with an airstone, for about 24 hours before using. New RO water has a low pH and is oxygen depleted. After aerating, the pH will rise dramatically. Can't say it help the buffer, but the buffer in your tank should compensate for that. I have heard Anthony Calfo say that more than 36 hours of aeration, the buffers may be driven off. Take it for what it's worth.

MCary
09/09/2006, 11:17 PM
ufchristyb is right. RO water because of it purity has no buffering capacity. Buffering just means "the ability of a solution to resist pH change". Even a small addition of base or acid will swing pure water drastically in either direction. You may have a different experience but the science doesn't bear it out. Its anecdotal.

Before any of you can help her she needs to give up the secrets she's been keeping since the beginning. What is the pH? What are the swings? What is the time the measurements were taken?

Mike

drummereef
09/09/2006, 11:21 PM
<a href=showthread.php?s=&postid=8113932#post8113932 target=_blank>Originally posted</a> by MCary
ufchristyb is right. RO water because of it purity has no buffering capacity. Buffering just means "the ability of a solution to resist pH change". Even a small addition of base or acid will swing pure water drastically in either direction. You may have a different experience but the science doesn't bear it out. Its anecdotal.

Before any of you can help her she needs to give up the secrets she's been keeping since the beginning. What is the pH? What are the swings? What is the time the measurements were taken?

Mike

THANKS MCARY! That's what I've been asking for two! Accurate testing is the only way to come up with a accurate analysis to the problem.

boxfishpooalot
09/10/2006, 12:39 AM
RO water will not change your alkalinity, or ph. Ask Randy holmes Farley.

Low Ph is always because of high indoor CO2. Open all the windows in your house and your ph will rise.

The only other way that your ph would be low, is if your alkalinity/dkh is below 2.5meq/l / 7dkh. Otherwise its just Co2 iin the house.

becki boggs
09/10/2006, 07:00 PM
my ph goes down to 7.8 and i used reef buffer .

jeffbrig
09/10/2006, 09:16 PM
Oops! The post by ufchristyb above was actually me. I was using my wife's laptop and left her logged in by mistake....

becki, to confirm the source of your pH problem, first measure your alkalinity. Low alkalinity -> low pH

You can also test for CO2 as a cause. Take a cup of tank water, and test its pH. Then take the cup outside with an airstone/bubbler and let it run for an hour. Test the pH again and see how much it has changed. This will tell you how much your pH is being depressed by high indoor CO2.

MCary
09/11/2006, 10:43 AM
7.8 is low and Jeff gives good advice.

Once you get your pH where you want it, be sure that when you monitor it, you are taking your measurements at the same time everyday. The highest pH of your tank will be just before the lights go off and the lowest will be just before they come on. Mine goes from 8.05-8.3.

Mike

hambalid
11/16/2006, 09:23 AM
You might want to think about buying a calcium reactor considering the size of your tank.

Or search on Reef Central for more ideas on how to get the alkalinity up. Randy Holmes Farley has written extensively on this subject. One article in particular shows the approximate costs for maintaining calcium and alkalinity levels for various tank sizes.

Just so it's clear...

Alkalinity in this context is the ability to buffer (resist) acidic pH swings. More or less, the higher your alkalinity measurement the less your pH will fluctuate.

Best,

dan.