balance - it shouldn't be this tough

[robbuck]

I don't get it, the last few days, no matter what I do my pH continues to drop

My current parameters are:

SG = 1.0245/ sa = 50.3 (refractometer/pinpoint salinity monitor)
temp = 80.5
CA = 392 (salifert strontium test kit)
ST = 4 " " "
Total Alk = 6.5 , borate alk = 1.5, thus carbonate alk= 5 (seachem magnesium test kit)
MG = 1250
phosphate = .1
nitrate = 10
nitrite = 0
Amm = 0
resid ozone = 0
up until four days ago my pH was 8.2 with an .06 - .12 nightly drop, currently pH is 7.97 and dropping - even with the lights coming on this morning 8am CST.

I did a 19% (10 gal) water change two days ago after noticing the steady drop - change water supplemented with seachem reef calcium, reef complete ( tested at 420). Since then I have been dosing Seachem Marine buffer daily according to instructions. pH will initially rise to above 8.2 (pinpoint pH monitor,confirmed with liquid Aquarium Pharmaceuticals pH test kit) but over time drops back to the 8.0 range, and this is during the day. so it doesn't recover during the day like normal. I know the whole circulation/ aeration bit. I have my spray bar above the water line spraying at about a 35 degree angle down to the water, I have a maxijet 900 with nozzle about 2.5 inches below water line mounted in the corner aimed toward front left corner and slightly deflected off side glass(54 bowfront corner) surface water really churning and you can follow the current microbubbles all the way across the front to the right side, and this down to sand level. I have a maxijet 600 mounted with nozzle about 3 inches down below water line but angle slightly up toward surface aimed toward the right front corner, definite surface agitation. Remora hang-on with maxijet 1200 close to the 600 on right side of tank with return water fall slightly out of the path of the 600. I am also dosing seachem reef calcium daily and Kent Strontium and moly according to instructions.

For a test, I took a plastic cup with almost 16 oz of tank water (pH around 8.08) and aerated it with an airpump/stone for 30 minutes or so (bubbling madly) and then testes with liquid AP ph test kit and it came out 8.4, but if I tried that with my tank it look like a bubbling cauldron.

I know night swings are normal but no daytime pH recovery I don't get.

[robbuck]

since initial post, pH has dropped to 7.96, BTW recalibrated pinpoint pH monitor using 7.0 and 10.0 calibration fluids two days ago.

[Tennsquire]

Hmmmmm.... I don't know if this is the answer to your problem, but it's been my experience that my house is largely to blame. I built a new house two years ago, and it's fairly air tight. CO2 does build up in the house over time. This is very evident when I open the windows, and watch the pH in my systems rise in a couple of hours time due to the oxygen content of the outside air (and I add nothing to the tank in the way of additives for it to rise). In the fall and spring, it's not a problem, as it's nice outside and the windows are open alot. But in the winter and summer, when it's largely recirculated heated or cooled air, CO2 does build up. Try it and see if it raises the pH.

[robbuck]

since last post pH is currently 7.96... I'll give the window thing a try, thanks...

[Radcast2]

I will try that as well as i am having low pH problems as well.

Also robbuck fair warning, watch that Seachem buffer i used just the ph buffer and sent my Alk thru the roof. I also used the marine buffer to help get my Ca up and it also sent my Alk thru the roof. Just be careful using it.

Rich

[SALT]

I am currently going through the same thing. All of the replys above are accurate for what I have read. The only thing that was not mentioned is bio load. From reading the information in this link, http://www.advancedaquarist.com/issu...2002/chem.htm, it appears that you can have pH problems with an over stocked tank. http://www.advancedaquarist.com/issu...e2002/chem.htm

[robbuck]

the seachem marine buffer does mention on the bottle that each dose will raise the alk by 1, but I've adding just under the recommended dose because dramatic pH changes are just as troublesome.... as far as bioload, well I've had the same fish population for over a month now. The bulk of my occupants are corals, which have been added in basically frag sizes over a period of three to five weeks. My ammonia and nitrite levels have remained at zero throughout the additions. It has been the calcium level that has been taxed and like I said, I've been dosing calcium daily and testing almost daily until I determine what is the best maintenance dosage. my test results are typically 375-390 range. I've hadn't had much luck in finding info on how corals impact the bioload - I suppose if they respire a lot that could impact the CO2 levels in the water... it's unclear. still testing the open window theory...

[Aframomum]

Hi there,

Do me a favor and mix up a gallon of fresh salt water with the same salinity as your tank, and test the pH after mixing and then 24 hours later. Do not aerate the saltwater, but you can put a powerhead in the bottom of it for circulation. See if the pH changes with just the newly mixed saltwater.

If after 24 hours the pH of the newly mixed saltwater doesn't change, then you may be in need of some major water changes for your 54 gallon tank. How are the animals in your tank acting? How exactly are you using the pH probe, dipping it directly into the tank or taking a sample and reading that? I'm thinking either the chemistry in your tank is off or your using the pH probe incorrectly. Just throwing out some ideas,

Mark

[Russ]

A faulty pH probe?

[robbuck]

I use a pinpoint pH monitor which I just recalibrated 2 days ago using 7.0 and 10.0 reference fluids. This unit has a suction cup for attaching to the side of the tank submersed (although it comes loose regularly) and stays in the water. I try to keep it in the rear corner in an area of good movement. The instructions say simply to not allow bubbles to accumulate on the sensor. I also frequently compare its reading to a Aquarium Pharmaceuticals liquid pH test kit and they are usually pretty close.

Typically, my water changes are once a month, 10 gallons (19%) a shot. I fill two five gallon containers over several hours (RO/DI unit takes time) and then mix using Kent Sea Salt mix. I shoot for 1.022-1.024 sg(using a refractometer) depending on the status of my tank. My target is 1.0245. I also have a Pinpoint salinity monitor which hangs in the tank - target is 50.3 salinity. But I always compare the two readings because both require calibration. I test newly mixed water for Spec. Grav., pH, and calcium. pH is fairly constant at 8.2 and I keep the container agitated ( by shaking it) regularly during the mixing/changing process. I have to add calcium because the RO unit removes a lot. It usually tests at 350-360 and I add supplement to achieve 420. I top-off with fresh unmixed/treated RO water every 4-5 days, 1-2 gallons,also depending on tank conditions.

Currently, all life behavior seems good, fish are active all feeding ( I reduce feeding for a few days following new additions and typically do 10 gallon water changes the day after adding something new. All coral are opening and extending normally and generally look good. As long as I dose daily, my tests for calcium and strontium (salifert strontium kit) result in 380-390 calcium, 4 strontium.

I'm considering dosing kalwasser at night, but all I have to use for automatic dosing are a couple of Eheim liquidosers. They can dose up to 8 times a day but the amount is fixed. Using plain water , one unit dosing 8 times into a measuring vial produced a little over 3 ml. I have yet to determine how that will affect the tank since I'm still dealing with stability issues. I currently dose daily using Seachem Reef Calcium and Reef Complete, alternating them.

[Russ]

I use the same supplements, and my pH varied from 7.85 to 8.05. However, I also dose Kalk at night (about 1 teaspoon).

You wrote: "Total Alk = 6.5 , borate alk = 1.5, thus carbonate alk= 5 (seachem magnesium test kit)"

Um, what units are those Alk measurments in (dHK or meq)? If it's dHK, then your Alk is low and that's why you can't stabilize pH. If it's meq, then your Alk is a little on the high side and that may be contributing indirectly to the problem.

[robbuck]

I just checked on the window theory, one partially opened window in the room where the tank is, and the ceiling exhaust fan in the hall running on low, been a couple of hours now - pH up to 7.99. Maybe but it should rise anyway from photosynthesis, right? the tank has a glass cover that covers approximately 3/4 of the tank. I currently have the hinged part of the lid up, could that contribute? I am building a new full top canopy to accommodate more lighting and I have installed three cooling/ exhaust fans that turn on with the lights. I'm going from a power compact (triple 55s, 2 actinics, 1 10k) that rests on the center of the tank to a homemade full coverage canopy/top which has full lighting coverage, three stages and will include: 2 x 55 watt actinics, 1 x 65 watt actinic, 2 x 55 watt 50/50s , 1 x 55 watt 10k, 1 x 65 watt 10k, from 165 to 405 watts. I cut a 1/8 inch thick piece of plexi to cover the entire lighting section and there will still be about 5 inches of clearance from the top of the tank. Two of the cooling fans are isolated to the lighting section (the 3 1/2 inch metal cased Radio shack fans) one exhausts, one blows in, and a 4 1/2 inch metal cased Radio shack fan exhausts - 3/4 from the open space above the tank and 1/4 from the lighting section. Hopefully this will help with surface air movement over the tank. I plan on removing all the glass but the center section. This is where I'll set the dosers which are battery operated.

[robbuck]

meq/l

[Aframomum]

Hi again,

My first thoughts were possibly incorrect usage of the pH probe, but since it is designed to stay in the tank then I have to presume it is giving correct results.

You said that you have 3/4 of your tank covered, do you have a sump or some way for proper gas exchange between water and atmosphere? I'm taking a guess but that may be the cause for the low pH.

Your maintenance routine sounds solid, so you may want to see what happens if you remove the covers. It could be as simple as that.

Mark

[MalHavoc]

Perhaps this is obvious, but calibration solutions for pH meters go out of wack too. When was the last time you made up a fresh batch of calibration solution?

Ultimately, look at the animals in your tank. Do they look healthy? are your fish happy and eating well?

Numbers matter little, and a pH of 8 isn't "all that bad".

[robbuck]

these are pre-packaged calibration fluids purchased from premium aquatics, they're probably a month old or so. I've had the covers open today so it's about half exposed. It is now reading 8.01 verging on 8.02. The window has been open most of the afternoon so it could be a combination. The trick will be to see what happens over night. I know a drop is expected, but how much will be the indicator. I realize "8" isn't bad but the current trend suggests that it will be down to 7.8 or below by tomorrow night. There in lies the concern. BTW, I just retested the alkilinity, results are 5.5 meq/L total alk, 1.5 meq/L borate alk, 4.0 meq/L carbonate alk. That's down from 6.5 total earlier today so maybe it's starting to stabilize...

BTW, who tests for Strontium?

[Aframomum]

Hi Robbuk,

I can feel for your situation being all worried about test results. I used to test for many things that I eventually found to be worth more trouble than they were good. Even ran out to get the pinpoints ORP sensor when they first came out and worried about getting the millivolts to were they were supposed to be.

Eventually though, I learned to trust what my tank was telling me and not a test kit. Now all I test for is S.G. (frequently) and Ca (on occasion). I believe that if I had a Ca reactor or if I were trying a newly DIY kalk reactor I would be checking my pH often, for obvious reasons, but now I feel that water changes keep things were they need to be. Only when my corals and/or fish start acting strangely do I start checking things. Xenia, by the way, is a great early detector for things amiss.

So the answer to your Sr test question is no.

Mark

[robbuck]

yeah, I know what you mean. My wife looks at the tank and says, " I don't know what you're worried about, everything looks great to me." I tell her we're still in the early stages and things need tending to, she says, "does this mean it will be a year before we can take a vacation?" I say, "No, just another 8 months"... he he. I'm really just trying to understand the daily ebb and flow of things, so that I anticipate changes and react correctly. The more I can setup to be routine or "automated" the more time I'll/we'll have for other things.

A xenia is my next planned addition, probably after July 4th, that and a rasta or a green finger leather. Then all I have to do is catch my domino menace. Damn that guy at the LFS who told me to cycle my tank with it.

[yardboy]

Hey Rob, I admire your concrn over the tank parameters. I'm new at this also, and obsessed about the tank parameters. I'm a water chemist anyway, operating a highly dynamic and energetic system, so I transferred my mentality and routine to the tank at home. Took me a while to realize that the tank was a lot more buffered than my work! I also realize that there are often so many factors involved that contribute to your observations. For instance, I wondered about your statement about the RO removing so much of the calcium? The salt mix is where the calcium initially comes from, and the substrate supplies it also, along with any additives, and these are added after the RO.
Also, I found that using the glass top inhibited gas transfer and led to overheating so I scrapped mine.
My first reaction to a pH value that is unexpected is to suspect the meter. I've made my living for the last 22 years using pH meters of the highest quality and have been disappointed often to find how unreliable they can sometimes be. An "on-line" probe, particularly one immersed in a solution of high ionic strength and biological activity are the least reliable. I use research grade meters immersed in ultra-pure water solutions and they get fouled over time. The Orion that I use at home I tried to keep immersed, and it became fouled after just a day. Of course, none of this might be your problem, though I shudder to think that CO2 is building up in your house to the level that causes your tank pH to drop! (Might be though!)

[robbuck]

So here's the latest... the last two nights, possibly as a result of opening a window in the room for a couple of hours each day and/or removing two sections of my glass top ( the middle section supports my power compact), the pH has risen to 8.04 -8.06 and the lowest it has dropped by early morning has been 7.98 - 7.99.

I still have been dosing calcium either in the form of Seachem Reef Complete or Reef Calcium. I tested my alkalinity this morning (Seachem Magnesium and Alkalinity test kit) and total alk was 4.9 -5.0 meq/L with a borate alk of 1.5 meq/L. I am beginning to understand the relationship between the measurements and am in the process of deciding what form of calcium to dose at night. While I have not tried kalwasser yet, I believe the Seachem products are either not that strong or my inhabitants are consuming all that is dosed. Again my CA test results this morning were around 380. Who has an opinion as to whether this is a good consistent level or do I need to be closer to 400?

I should have my homemade canopy completed tonight (will post pics in my gallery) since I'll be using parts from my current power compact, I have to wait til the end of this light cycle. The new canopy will more than double my total wattage as well as have forced air movement over the water's surface for improved gas exchange. Now I'll just have to see what that does to my evaporation rate.

and yardboy. to answer the RO-calcium question, before I got my RO unit, I was using dechlorinated tap-water. While I have one of those "Omni" whole house filters on the cold line coming to the house, It merely removes most sediments and reduces chlorine. When I made a mix using that, typically my calcium tested out at 420. When I started using RO/DI water to mix, my calcium tested out at around 350. So it became necessary to add calcium supplement to my mix water so as not to dilute the total tank water's calcium level.

Thanks for everyone's opinions and suggestions

[Aframomum]

Robbuck,

Glad to hear that you got rid of the top, it really does inhibit the gas exchange. I think if and when you place a fan blowing across the water's surface it will increase the gas exchange.

I wouldn't concern yourself with a Ca of 380 at this time, it is probably on its way up and you just have to be patient. Increasing the Ca to stable levels can take time, I would suggest in addition to your Seachem additions you start dripping Kalk at night. You mentioned corals, what do you have? Also, you don't need to break the alk into total and borate, total alk reporting is just fine. Remember the direct/inverse relationship between Ca and alk: As alk increases Ca decreases. So an alk of 5, being just a bit high, could be the cause of a slow Ca increase.

Hey, congrats on almost finishing the new hood. I know its exciting to see it all operational. Can't wait to see your pics,

Mark

[robbuck]

most all of them are frags, or just a little larger than frag size...

They are 1 each:

Lavender frogspawn
Candy coral
Anchor/hammer
Chili
common toadstool leather
yellow toadstool
yellow tubinaria cup
small colony of zoas

and a tiny I'm not sure what that was growing on the base of the toadstool - maybe a torch - but too small to tell, right now its tentacles are clear.

[yardboy]

Gotcha on the calcium question. I hope your water's not like mine, though. (don't know where you live) I had lots of calcium in my tap water, so I used it on my initial filling. Took forever to remove the phosphate that they use to prevent scaling! good move to begin using RO/DI

[robbuck]

canopy pics are in my gallery, since install, pH has already climbed to 8.02 from early morning pre-light reading of 7.99. Good air movement and canopy is staying cool, it does look like my evaporation rate has increased... next job, how to top-off...

[Aframomum]

Topoff

Take a 1 or 3 gallon container, poke a small hole in the bottom corner, and place above the tank or sump so it can slowly dribble back into the tank the 1 or 3 gallons over the day. You can even get creative and use a nipple with airline tubing, silicone it to the hole, and place a valve on the end so you have more control over the flow rate.

Mark