Mg is Too High 1600

[windyridge]

My Mg is 1600, too high. Not sure what's going on as my PH is now 7.8 where it was steadily at 8-8.2. SG is 1.025. Ca is 430. Alk 2.6. My parameters have been rock solid until the last week or so. I had been dosing with a Kent Marine additive about twice a week. Wed I started using a 2 part additive thinking that would help because of the buffer. Corals and fish look fine, there is plenty of corraline and there are no calcium deposits anywhere that I can see. We do water changes every two weeks ...about 5 percent. Can anyone shed some light on what is happening? I am nervous that the PH may continue to drop.

 

[tmz]

Are you dosing magnesium?What is the magnesium content of the salt mix? 1600 shuldn't hurt anything but you might want to consider a lower mag salt mix if that's the issue. The other numbers are fine .Personally I like the alk at around 3.25 meq/l, ie 9.1dkh. but many like it right where you have it.

As for the ph, it has to be CO2.Perhaps the room air is high due to closed windows or lot's of people in the house.. Could also be a probe in need of recalibration or the time ofday you are taking the reading? 7.8 is ok but could be trouble if it goes lower.

 

[windyridge]

It only started the past few weeks which coincides with closing the windows. Could be a CO issue. I will investigate that tomorrow as windows will be open. We are getting a 60 degree day tomorrow in Upstate NY.
There is some Mg in the Ca additive and some in the salt but again, I hadn't changed anything. The only thing that has changed that is obvious anyway, is the windows being shut and my son keeps his door closed a lot of the time. We also started burning wood in our wood stove but I am not sure that would contribute to CO.

 

[windyridge]

Would it help if i had my refugium light on at night instead of during the day since at night is when respiration is taking place? I haven't had opposite lighting because the tank is in my son's room with an open refugium. I am upgrading to a 92G not in my son's room in a few weeks and I will be able to do that. I could keep it in on 24/7. It has chaeto in it.

Also this house is very tight. I am going to run this set of experiments tomorrow (http://reefkeeping.com/issues/2004-09/rhf/index.php ):

Remove a cup of tank water and measure the pH. Then aerate it for an hour with an airstone using outside air. The pH should rise if the pH is unusually low for the measured alkalinity, as in Figure 3 (if it does not rise, most likely one of the measurements (pH or alkalinity) is in error). Then repeat the same experiment on a new cup of water using inside air. If the pH rises there too, then the aquarium pH will rise with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise inside (or rises very little), then the inside air contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should).

 

[tmz]

That test will give you an indication if house air has high CO2.

Magnesium will not rise unless you add it . What salt mix are you using?Different brands have different levels of magnesium.

High magnesium will not drop ph. It discourages calcium carbonate precipitation and thus saves some calcium and alkalinity and allows more to be held in solution. The alkalinity buffers against ph swings but it is not useful to dose it to raise ph since any effect is shortlived when CO2 from the air equilibrates with the water leaving the extra alkalinity with low ph.

A wood stove produces gases as the wood which is primarily a carbohydrate( cellulose) is oxidized/burns. It produces carbon gases along with nitrogen and heat. As the carbon gases react with the air CO2 is formed. So depending on how well vented the stove is it could add CO2 to the house air..

A lighted refugium with macroalgae on opposite photo period can offset nightime CO2 build up and add oxygen. How much depends on it's size. lighting and rates of growth of the algae.Some folks run em 24/7. I prefer a period of darkness for the algae and run mine for 16 hours per day.

Ifthe house air is high, fresh air will help. Sometimes an airline to the skimmer air intake drawing in outside air helps as does an open window.

Dosing kalk( limewater/ calcium hydroxide ) instead of two part can help too as the oxide uses CO2 in th water to form carbonate alklainity.

A CO2 scrubber onthe skimmer air intake line can help too.

 

[bertoni]

The pH is lower due to a carbon dioxide problem, assuming the measurement is okay. That's a reasonable level for a tank in a closed-up house, and should be fine.

I don't know how the magnesium got higher. There could be a testing issue. The magnesium level won't rise unless something's added.

 

[windyridge]

Did the experiment and bingo, it's the air in my son's room! Windows will be open the next few days and we will get the new tank set up in the living room asap (a few weeks I hope). The rest of our house is an open loft cathedral ceiling setup so I am hoping there is plenty of fresh air circulating around. Because my son closes his door at night and frequently during the day due to PS3 noise, I am hoping the problem will be solved by having the tank in the living room. If not, I am wondering about the tubing idea. Won't the freezing cold air from a wintry day/night make the heater work really hard? We get below zero nights frequently and 10 degree days. Or I could run a line to the crawlspace which is vented and is warmer as the furnace is down there and it doesn't get below 50 degrees. But I am getting ahead of myself. The wood stove is pretty tight and I am hoping the move will fix the problem. In the meantime I will check PH every day as I am a little nervous about having it so close to dangerous. I know you said it should be fine and it probably will but to answer my own question I will do the same test down in the living room. I am sure the air is different there.

 

[tmz]

I'm in Buffalo and didn't notice any trouble from he heaters when I used the airline to the skimmer .

 

[windyridge]

Oh and to answer the salt question, I use Instant Ocean Reef Crystals but I have always used that same salt, so the Mg is coming from the Ca additive. I have to adjust my dosage a bit. I have a new Ca/Mg test kit coming so I will see if the two tests agree with each other first and go from there.

 

[windyridge]

TMZ how did you run your line to the outside?

 

[tmz]

A hole through the basement wall and a length of tubing into the basement. It needs to be relatively large tubing 1 inch or more for a long run to avoid restricting air flowto the skimmer. I've abandoned it since mine had tubing that was too small and I tired of tinkering with it. . For me a CO2 scrubber works better:

I'd check newly mixed salt water for magnesium content. Sometimes salts can be poorly mixed in the bucket or batches can be off expected numbers on major elements. Reef Crystals shul mix to 1440ppmmag at 1.026 sg.

 

[tmz]

Sorry wrong picture:

 

[windyridge]

Yeah I was wondering where the scrubber was among those zoas. lol
What is in each plastic container?

I am still on the same batch of reef salt, so I have a new batch mixed up and will test the Mg conc in that later.

 

[tmz]

Soda lime, a CO2 adsorbent with a color chage indicator,; one of the bottles is starting to turn purple but is still good for a week or two. . It's commonly used for anesthia mesurements and breathing aparatuses. The air comes in the bottom through slats ripped into the juice bottle ;passes through it; and, goes out the top to the skimmer airline. There are two skimmers ;one is out of the picture.

Here is a thread on it:

http://www.reefcentral.com/forums/showthread.php?t=1889552&highlight=co2+scrubber

 

[windyridge]

Thanks for all the info! If I decide to scrub, that's how i will do it. Loos easy enough.

 

[tmz]

Youae welcome and good luck.

 

[windyridge]

Left the refugium light on almost all night. Had it shut off at midnight and come back on at 2am...my son never noticed! lol. The PH rose just enough to push it into the 8.0 color band this AM. I will just run it opposite cycles once the new tank is up and running and keep doing what I am doing until my son complains that the light is keeping him awake (if he even finds out).