Aquarium Chemical Parameters

Discussion in 'Chemistry' started by ScubaDog, Oct 20, 2014.

  1. ScubaDog

    ScubaDog RRMAS Supporter

    Over the years I noticed how confusing chemistry can be for most hobbiests. So I was thinking thats a discussion on basic water prameters would be helpfull. So I would like to start with the topic of pH.

    What is pH and why do we care? pH is a scaler measurment of H( positivily charged proton) and OH (a negativily charged hydroxide). Think of a water molacule thats split in half. We take H20(water) and remove a hydrogen atom and what is left is a negativly charged OH ion. Notice that when we split the molacule that its broken down into a one to one ratio, that is one H proton to one hydroxide anion. Why is that important, well being balanced one to one explains why waters pH is considered neutral(PH 7). If there was an imballance then the pH would ither be less than 7 or greater than 7 on the pH scale.

    I did get ahead of myself in the above paragraph, I need to go back and explane the pH scale. Anything less than 7 is concidered acidic and anything greater than seven is considered basic. Acididity refers to the concentration of H protons and Basididty is the concentration of OH ions and neutral is pH 7. If a substance is neutral it means that there is an equal number of H protons and OH ions. There are other definitions on how to define an acid or base , bronsted lowerey, lewis acids and bases, and arehenious(sp)

    Acids and bases are also one of the main classifications of chemical reactions.


    Ill stop here for the moment, learning chemistry is done with small doses. Please feel free to chime in and add to this or ask questions. Later I plan on adding more definitions and concepts and how it applies to the health of our livestock and coral growth.
     
  2. graciesdad

    graciesdad Treasurer Staff Member

    Looking forward to reading more. I am definitely tagging along here.
     
  3. ScubaDog

    ScubaDog RRMAS Supporter

    The actual mathmatical definition of pH is the -log of the H+ concentration. luckly we don't have to calculate that, our test kits and pH probes save us that headache.

    Ok why is pH important. pH plays a large role in chemical reactions especally in our hobby. There is inorganic interactions, such as maintaining Ca, alkalinity , and levels of solubility. Also there is an organic/bio chemical interactions.

    A change in pH can turn on or off protines that directly or indirectly control bio chemical reactions. When it comes to our live stock physiology and pH go hand in hand.
     
  4. ScubaDog

    ScubaDog RRMAS Supporter

    Normally if one has the correct salinity (spgr) specific gravity, and correct Ca,Mg and total alkalinity the pH should be within the normal range. But in my case there is a curve ball. I have higher CO2 levels in my home, and unfortunatly a low pH problem. What happens is the CO2 (carbon dioxide) invades my aquarium through surface water interactions and also through the air intake of my skimmer. The reaction that takes place yields Carbonic acid that lowers my pH...and in a nutt shell slows down coral growth.

    But all hope is not lost, there is a few ways to fix the problem, open some windows, add a freash air line to the skimmer, or use soda lime media to scrub the CO2 before it reacts through the skimmer water interface. In my case soda lime is the prefered option. A future project is a DIY CO2 scrubber.

    Please feel free to chime in yall!
     
    Last edited by a moderator: Oct 22, 2014
  5. huntindoc

    huntindoc RRMAS BOD Membership Director Staff Member

    Great thread! One question...will soda lime affect alkalinity?
     
  6. graciesdad

    graciesdad Treasurer Staff Member

    Also, how did you discover too much CO2 in your house?
     

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  7. ScubaDog

    ScubaDog RRMAS Supporter

    In air tight homes there tends to be CO2 build up, especially if you have several people in your family, even the cats and dogs contribute as well. How would you know if your CO2 is high, 1, if your fighting low pH levels in your tank and your Ca, Mg, Alk is all in range. A Calcium reactor could also cause low pH as well.

    Soda Lime will not hurt your Alkalinity. Soda Lime is a fancy media that is used to scrub CO2 from air. other uses for soda lime are for enriching the gas for cutting torches, breathing machines for anesticia sp.

    The way soda lime would work is by using it an air filter into the skimmer air intake. The media never touches any tank water. Also the media will change to a pink color when its spent.
     

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  8. huntindoc

    huntindoc RRMAS BOD Membership Director Staff Member

    Cool. I was equating lime with pickling lime/kalkwasser...that's why I couldn't understand how you could get away with using that to fight low pH. When we have people over (like 15 or so tonight) the pH in my tank will drop about .08 to 0.1 from it's usual.
     
  9. graciesdad

    graciesdad Treasurer Staff Member

    Where does one get soda lime? Can you demonstrate how to use it on the skimmer air intake?
     
  10. ScubaDog

    ScubaDog RRMAS Supporter

    Soda Lime can be purchased through aquarium supply company's. I know Bulkreef supply has it. Vet/medical supply retailers, and local welding supply business as well.
    To use Soda lime you can buy a "reactor" or make your own.
    1. use a plastic see through container, so you can see when the media changes to a pink color from white, When it changes to pink it needs to be changed out.

    2. drill some air inlet holes on one side of your chosen container( any ole container with a lid will do, ex soda 2liter bottle).
    3. Once the air inlet holes are drilled(several) place a sponge or mesh material to cover the inlet holes inside of the container. The purpose of the mesh is to keep the media from falling out of the CO2 scrubbers air inlet holes.
    4. Next add the media to the scrubber on top of the mesh, then add a second mesh layer.
    5. Close up your jar/bottle with its lid.
    6. Drill a hole into the lid side of the scrubber, a sizable one to allowh good airflow through it.
    7. Plumb a fitting into the scrubber outlet with a line that connects into your skimmers air inlet.

    CO2 rich air will be sucked into the scrubber----then the CO2 will be absorbed by the media-----the scrubbed air will enter the skimmers air intake. End result less CO2 is added to the aquarium...less CO2 = less carbonic acid= increased pH= less H protons = more Ca adding to our corals= better growth
     
    Last edited by a moderator: Oct 24, 2014
  11. ScubaDog

    ScubaDog RRMAS Supporter

    I understand. The term lime is way overused. Soda lime is a solid pellet made up of Calcium Hydroxide (CaOH) Say 90% composition, water(H2O) about 5%, and the remainder Sodium Hydroxide and Potassium Hydroxide.

    Like kalkwasser pickeling lime soda lime is made up of Calcium hydroxide, but has a few extra ingredients like water sodium hydroxide and potassium hydroxide. Soda lime works by binding CO2, it does this by forming Carbonic acid then sodium carbonate then ends up as calcium carbonate...over time all of the calcium hydroxide is used up and the PH becomes acidic , An indicator is added to the pellets to show a change of pH, that's why when it turns pink when all the CaOH is used up.
     

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