GHA

Discussion in 'Water Parameters and Additives' started by jumboswart, 30 Oct 2010.

  1. jumboswart

    jumboswart

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    I have tested my water parameters with the salifert test kits, and they are as follows

    PH 8,0-8,3
    KH 6,4
    NO2 0
    NO3 0
    NH4 <0.25
    PO4 0-0.3
    Salinity 1.025

    My question is this the cycle has been going for about 3 weeks and I have GHA growing from my aragonite sugar fine substrate,

    [​IMG]

    I have a carbon reactor and NP bio pellet reactor, would I need to do vodka dosing as well?:(
     
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  3. ziyaadb

    ziyaadb

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    its part of the cycle. i also had it. give it some time and it will dissipate
     
  4. jumboswart

    jumboswart Thread Starter

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    Thanks ziyaad thought as much just wanted to make sure and not over think things:peroni:
     
  5. Nemos Janitor

    Nemos Janitor

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    PO4 is a problem. It needs to be < 0.015mg/l P or <0.046mgL/ PO4 3-.

    Phosphate at levels of 0.03mg/l P and over act as fertaliser for algae.
     
  6. jumboswart

    jumboswart Thread Starter

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    According to the test its not quite 0.03 but also not 0 so somewhere in between, the cycle has only been going for 3 weeks so will wait for January before I start stocking and make sure all parameters are at the acceptable levels
     
    Last edited: 30 Oct 2010
  7. Nemos Janitor

    Nemos Janitor

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    The Po4 could be coming from your carbon. Not a good idea to run carbon full time as it leaches PO4. Only run it for short periods to polish the water.
     
  8. ZaxXx

    ZaxXx

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    Heyyy is that really the only reason for a carbon reactor??? To polish the water?
    :032:
     
  9. jumboswart

    jumboswart Thread Starter

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    Will then have to work out how to turn the pump on and of for say 8 hours on 16 hours off, need to read the profilux manual :(
     
  10. magman

    magman

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    If your tank is only cycling, turn the lights off, in a few days try and siphon out as much of it as you can, skim wet, hope it helps
     
  11. Nemos Janitor

    Nemos Janitor

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    Yes...No... Maybe....
    Ok the primary use of GAC (Granular Activated Carbon) is to remove DOC (Dissolved Organic Carbons). Yellow or discoloured water is a result of high DOC. One can argue that ones skimmer or ATS is not efficient enough etc etc. But the fact remains that GAC removes the residual DOC and clears the water by removing DOC and trace elements.

    Using GAC full time.
    There are different grades of GAC and the better grades that do not leach PO4 and SiO2 are expensive. GAC also has a very short life and depending on the quality /grade of GAC it has to be replaced very regularly else it leaches all back into the tank. One also has to do larger water changes to replenish trace elements and other good organics removed by GAC.

    Using GAC for short periods.
    Some aquariusts use GAC for short periods only to polish the water and remove that yellow tinge in the water. These are normally the softies guys as corals can suffer if all DOC are removed.

    So the concerns in using GAC are
    1) they leach PO4 and SiO2
    2) They remove trace elements necessitating larger regular water changes and additive supplementing.
    3) They clog and require regular replacement
    4) Good quality GAC is very expensive.

    The concerns are what normally lead to GAC being run for short periods and when emergencies dictate. I know Hennie is one that has serious feelings about GAC and posted on a few threads. I will try and find them for you.

    My feeling is that if you can afford the good quality GAC and extra water and trace elements and time to regularly change then by all means run GAC.

    One tip if you run GAC in a reactor the reactor must be completely packed with GAC else the particles rub together and grind to a fine particles that find there way to the DT.
     
  12. Singularity

    Singularity Hmmm amper!

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    carbon will not release anything it adsorbed, not in the aquarium enviroment anyway.
    Posted via Mobile Device
     
  13. ZaxXx

    ZaxXx

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    OMG:huh::idea:. . . I feel smarter now!!:conehead:
    Thanks man:thumbup:

    So which way would you say its best to run carbon? or can a system run perfectly even without it??
     
  14. Nemos Janitor

    Nemos Janitor

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    It all depends what you are keeping and circumstances. About 95% of our systems run without GAC.

    I disagree. Ref to Spotte 1979. Seawater Aquariums, The captive environment. This is the bible of marine chemistry that most authors refer to.

    one can download a PDF of the book from here. Well worth the 34E

    Sorry that is the review...
    http://www.springerlink.com/content/t672883u44465rq6/


    This is the Book.
    [ame="http://www.amazon.com/Captive-Seawater-Fishes-Science-Technology/dp/0471545546"]Amazon.com: Captive Seawater Fishes: Science and Technology (9780471545545): Stephen Spotte: Books@@AMEPARAM@@http://ecx.images-amazon.com/images/I/419HC20E0GL.@@AMEPARAM@@419HC20E0GL[/ame]
     
    Last edited: 30 Oct 2010
  15. Singularity

    Singularity Hmmm amper!

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    If carbon was to release substances it adsorbed, couldnt it release it at any time ? why would it only release adsorbed substances once it is saturated ? And if it released adsorbed sunstances easily i am sure we could rejuvinate carbon rleatively easily wont you agree ?
    This is also one of those debated points on alot of forums with two sides, i just tend to lean towards the side that it doesnt release adsorbed substances.
     
    Last edited: 30 Oct 2010
  16. xtreme

    xtreme

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    Sorry guys, so if carbon removes DOC and release it back isn't it better to run purigen from seachem?
     
  17. xtreme

    xtreme

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    Oh, I put seagel from seachem in my system and it wasn't even 3 days and my PO was 3 not even 0.3 but 3 and I removed it and run purigen with PO remover from seachem and test last night at .25
     
  18. Nemos Janitor

    Nemos Janitor

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    Well GAC is Granular Activated Carbon. Which means it is charged. I am not going to go into a chemistry lesson nor the different irons that are added to produce the different activated results as we will be debating here next year. In short the activated bit declines and only lasts for a very short time. The bound molecules (the carbon part of the DOC) then comes into solution and leaches back into the water column. There are ways that GAC works, absorption and adsorption. Absorption traps the molecules in the carbon pores and eventually clogs/blocks them while adsorption chemically bonds them and when the activation is depleted releases them.

    The Absorption bit is very susceptible to release if the GAC is loosely packed in a sock or reactor as the bumping and rubbing grinds and releases the trapped DOC irons.

    But hay read Spotte, Heavy but very enlightening. An aquariust's must have in my book. exc pun
     
  19. Nemos Janitor

    Nemos Janitor

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    Bud i cannot comment on the above products. From experience we use what works for us. We have tried a multitude of products over the years, all have varying outcomes.

    I believe chemical filtration should be used as a tweaking tool. Not a means to fix inadequacies in filtration. So my priorities are around real good mechanical filtration first then biological and lastly chemical.
     
  20. Reef Maniac

    Reef Maniac MASA Contributor

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    Interesting thread...

    Well, if his great grandmother wants to be successful in this hobby then IMHO it's actually a good thing to learn as much as she can - also about GAC :whistling: (and I'm sure that the OP appreciates the information as well ;)

    I fully agree with Nemos Janitor regarding the above.

    I have done some comparative testing of different brands of GAC, using a photometer which can measure to a resolution of 0.01ppm and an accuracy of ±0.04ppm, and even the most expensive product had detectable levels of PO4. The cheaper products leached as much as 100x more PO4 than some of the best brands tested (if I remember correctly - the tests were done some time ago, and I do not have the data with me...)

    I really don't care whether it releases previously removed DOC or just stops removing more, but I can also confirm through years of personal experience that GAC does lose it's "potency" pretty quickly.

    Although this is quite possibly true, I do not consider it to be of much significance, due to the following:

    • The amount of trace elements in a tank will usually be significantly higher than the adsorption capacity of the (limited amount of) GAC used in a normal filter, and IMHO normal partial water changes would replenish much of what has been removed
    • Feeding your corals and fish on a daily basis replaces much (all?) of the trace elements removed. I always find it amusing that people go over-board in trying to replace iodine removed by their skimmers, not realizing that most fresh/frozen food such as shrimps, krill, etc (or even dry flakes...) contain enough iodine to replenish that which the skimmer has removed.
    Here are some interesting (though old) links to articles about DOC and GAC

    Aquarium Frontiers On-Line: Feature

    Organic Compounds in the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

    http://www.carbochem.com/activatedcarbon101.html

    http://www.hallman.org/filter/gac.html

    Experiment: Is all Granular Activated Carbon (GAC) created equally? - Reef Central Online Community

    Hennie
     
  21. xtreme

    xtreme

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    I'm running my holding tank for 3 months now, first month with water and substrate and no lights, no sump, with 2 wave makers and cheap hang on skimmer and heater, 2nd month I put in my Fiji LR and did a 30% water change and tested the water was fine and then put in the seagell of seachem and from there the PO4 went to the moon, removed it and put in PO4 remover and 250ml purigen in the hang on skimmer, my PO4 is dropping slowly, received coral that I ordered from a few guys and put it in there and a lot of kenya LR, and run MH with 2x Antics and my water is crystal clear, just battle with the PO4. I do dose stability from seachem. This is maybe a time bomb to happen but the coral will only be in there for a month or two more but maybe I'm wrong but it looks like the purigen is doing it's work so why use carbon?

    I found this thread a great start for a newbie when tank busy to cycle, I'm still new and like all we are we can't wait for the tank to finished cycling so we can add stuff, now we add the A/Carbon and have to battle to get the PO4 to 0 and then just give up and the GHA is taking over.

    Remove the A/Carbon let the water turn yellow let it do it's cycle and when it's done cycling and you tested your water then try to clear up the water and run your skimmer on overdrive, you will have to refill almost every 2nd day of that the skimmer takes out and that's a better water change then just siphon out water, the skimmer remove more then the hose pipe. Read as much threads you can due to every members tank is running on different products and you may found one that works for you.
    A Newbies 2 cents
     
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