Ph 7.48-7.88 is LOW...great growth and health still

[serum153]

I recently added a ph probe to my reefkeeper lite unit and my ph is kind of disturbing, but weird. The probe is accurate as I have recalibrated it and confirmed it with 2 different test kits. My tank is and has been thriving with great growth results and no fish loss. My ph gets as low as 7.48 and reaches a high in the day at 7.88 - 7.98 (if i open a window). My fuge is on a reverse light cycle, but does not keep the ph from fluctuating at night still. New saltwater reads at 8.10 while being aerated in the garage. I do 18 gallon weekly water changes and that seems to keep my calcium and alk in line.

Salinity - 1.026
Calcium -440
Alk - 4/meql

I add randys 2 part (recipe 1) every once in a while to keep my alk and calcium in line. I haven't tested my mag in a while, so another question is...does magnesium play a role in my ph? Should I be concerned or just disregard the ph. I can't imagine better growth but wouldn't be opposed to having more growth

It is cold in reno, so i can't open a window all the time, but even when I do doesn't even bring me to 8. Thoughts
03/09

07/09

03/10

01/09

07/09

03/10

[sowellj]

I am a fan of the 'if it isn't broken don't fix it approach' so I would not worry too much about it. Having said that you could always try using kalk for top off for a bit to see how your tank does.

[keto]

wow great growth though ...

[CorkPullerPHL]

It's workin'!

[serum153]

Thanks for the replies so far. I wish I could find the cause as it isn't normal, but it is obviously working. I have a controller that can do anything, but my luck I would see ill effects by raising my ph.

[mthomp]

if it concerns you try adding marine buffer to the water you use when doing a water change.

[ReefTECK]

Alot of sps tanks suffer from this condition, actually they don't suffer they do quite well. It's usually a consequence of co2 injection for ca rxr's though instead of just a naturally occurring phenomenon.

I would ensure that you have adequate oxygenation, other than that, I wouldn't worry about it too much.

[HighlandReefer]

It appears that your tank is doing fine.

Some natural reef areas dip below the recommended lower pH level of 7.8 and rise to above a pH level of 8.5. The coral seem to do fine. The problem that results when your pH dips below 7.8 is that the calcium carbonate production made for the back bone of the coral begins to slow down and/or acutally dissolve very slowly. I have not seen any research that indicates exactly what occurs at these levels a little below 7.8. Certainly as the pH continually dips below 7.8 the rate that the calcium carbonate backbone of coral will dissolve a little faster until the pH reaches the levels found in calcium reactors where calcium carbonate dissolves very quickly. For this reason, it is recommended to keep your pH levels between 7.8 - 8.5.

So to some it up, you are in a pH level grey zone, which no one really knows how detrimental it can be to your coral. IMHO, I would try to keep your pH level up to between 7.8 - 8.5. Replacing your supplements for alk and calcium with kalk water will help bump your pH up the most, but you will need to dose kalk to maintain your alk level and not your pH level.

Bringing fresh air into your aquarium through a skimmer seems to help. If you have a ventless fireplace nearby your aquarium, this will greatly decrease your pH level in your tank.

Randy provides more details in this article:

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

[HighlandReefer]

I would also do a pH test on a sample of your tank water removed from your aquarium to make sure there is not electrical interference.

[serum153]

Thank you highland for the very detailed response and I will start reading on the kalk water. I will also take the probe out of mg sump tonight and perform the test. Should I have a powerhead in the test bucket or heater or should I just take a cup of water out and set the probe in for a couple of minutes?

[HighlandReefer]

Your welcome.

You simply need to remove a cup or so of tank water and give the pH meter 5 minutes or so to adjust to the pH level.

This article provides more details regarding kalk water.

What Your Grandmother Never Told You About Lime
http://reefkeeping.com/issues/2005-01/rhf/index.htm

[Randy Holmes-Farley]

I think there is still a very good likelihood that the pH 7.48 is not accurate. Coral skeletons and live rock and sand dissolve at that pH, although your higher than NSW alkalinity helps offset that likelihood.

That said, if you are happy with hard coral growth, I would not worry about it.

[serum153]

After reading the grandma article a couple of times I started to think how I was going to implement it into my system. I have 2 floatswtiches hooked to my reefkeeper lite right now to control my auto top off. One tells the reefkeeper to shut off the channel and the other is a failsafe in case the first switch fails. I will look for mixing directions tonight and some Ms wages.


Just saw your post Randy...have you found a failsafe way of testing ph? I was and am still skeptical of the probe as I haven't seen one ill effect to my system other than a small patch of cyano that my gfo is working on. I have calibrated it with digital aquatics fluid and also brand new bottles of Hanna 7&10. Maybe I will order a pinpoint Ph probe??7

[vegaskid11]

a handheld probe would at least give you a second reference. I know that my Hannah handheld meter reads a bit higher (8.45) at noontime on my system compared to my BRS probe on my apex unit (8.32)

[vegaskid11]

Also, do you have a temp probe or orp probe mounted near your PH probe, I have heard they can interfere sometimes.

[flfireman1]

I am by no means an expert on this matter, but was having the same problems you were. My PH would dip into the 7.5 range at night and the highest of 7.8 during the day. I also recalibrated my probe (bulk reef supply probe) with no change. I never made it a point to test my ph, and only tested alkalinity. However, after adding the pinpoint ph monitor is when I discovered this problem. To make matters more difficult, all my top off water goes thru a kalkwasser reactor.

After reading thru all of the articles and posts on the same issue. I was fortunate enough to have my sump and refugium placed in the garage of the house. The display sits in the family room and everything is plummed into the garage. Long story short, I drilled holes from the garage into the outside. One was for the air intake of my octopus skimmer and another hole for an air pump. The airpump sits outside forcing outside air into the sump and fuge and the skimmer intact hose is sucking in outside air.

This seemed to make an immediate impact on my tank. Now my ph sits at 7.9 at night and 8.1 during the day.

[serum153]

Thanks again for the replies. My temp probe is in my display and I did the test outside of the tank and came up with the same results. I borrowed a local reefers pinpoint ph monitor and came up with the same results. I did have to dose some alk today which brought me to 8.14 for a little while I looked for some mrs wages tonight with no success. I will try walmart tomorrow or look on brs as I am sure they have something.

[Randy Holmes-Farley]

That sounds like a good test. Here are my general comments:

When calibrating, make sure it does correctly read all of the pH calibration solutions you use after you complete calibration. Use at least 2 good quality, newish buffers, and if you are concerned about an odd reading, measure some tank water in a cup away from the tank as there are a variety of things that can interfere with some meters, like lighting ballasts.

If the pH really is 7.48, I'd use limewater to replace all evaporated water, and I'd consider more aeration with fresher air.