Newbie trying to understand Algae problem

Discussion in 'Algae' started by Midnight, 5 Nov 2008.

  1. Midnight

    Midnight Member

    Messages:
    48
    Location:
    North Yorkshire
    Since beginning my experiment with 'All-in-one' in my 130 x 50 x 50cm 325 ltr tank.
    http://ukaps.org/forum/viewtopic.php?f=11&t=3157
    I have been very happy with the results in terms of plant growth. However the algae issue is baffling.

    When I started, BGA was a problem. That's diminished quite significantly but the new problem is now BBA!

    Since adding a powerhead, flow is no longer an issue (probably contributed the the demise of the BGA). I also bought some KH4 solution and B Blue from AE and used that in the Dennerle drop checker which confirms the CO2 is about right for my low light tank (0.75wpg - 2 x 36 watt T8 tubes Trocal Amazon day and Trocal special plant).

    BTW. The drop checker certainly changed my approach to CO2. The Dennerle PH controller used to switch off the magnetic valve at PH 6.8 but the drop checker revealled at that PH level the CO2 content was too low. Although I am still tweaking, the drop checker is now creeping towards lime green but the magnetic valve is now switching off at PH6.6. Probably the acidity is influenced by the 2 large pieces of bog wood in the tank. Anyway the bottom line is I think the CO2 is fine but the BBA remains a growing (pardon the pun) problem.

    My next plan of attack is to add some additional light, probably an Arcadia single 54 watt T5 to the existing T8s and increase the All-in-one dose to 40ml per day of the double strength mix.

    Anyone any thoughts on this?
     
  2. tennis4you

    tennis4you Member

    Messages:
    137
    Location:
    USA
    BBA is my nemesis! I too had to increase flow with powerheads and Excel. Although I did read recently that Hydrogen Peroxide will help with bba (the less concentrated stuff, not the medical grade that burns your skin). Cheaper than Excel (big time!) if you need to blitz it to get back to normal. I realize that is just a bandaid for the problem but it gets rid of the bba and hopefully the extra flow will help.
     
  3. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Hi,
    My thoughts on this are; "What were you thinking?" BBA is caused by poor or unstable CO2 and/or poor flow and is exacerbated by high lighting. Therefore thinking that your CO2 is fine while experiencing BBA is a non sequitur. Adding more light creates a requirement for more robust CO2 which you clearly do not have therefore this can only make things more dire. BBA is not nutrient related but will feed on any additional nutrients added so this will only feed the monster. I would try to focus on the following concepts. repeat them to yourself as if they were mantras:

    1) BBA is a true indicator of poor CO2 therefore energy should be spent in stabilizing and increasing the CO2 concentration level. This can be accomplished by either disabling the controlling function of pH controller and using a solenoid (or by running the CO2 24/7 if no solenoid is available) and increasing the injection rate or by commanding a much lower pH set point on the controller such that the drop checker is green to yellow by the time the lights come on.

    2) Avoid making the situation worse by realizing the truth. The truth is that light and CO2 are intricately and fundamentally related in the physiology of plants. More light always requires more CO2. If your tank is telling you that you have poor CO2 do not make matters worse by adding more light. Only add more light when your CO2 is optimized. BBA cannot be fooled but pH controllers and dropcheckers are being fooled every day.

    3) If you are not suffering an NPK related algae there is no need to add more NPK which can only make your other types of algae grow faster.

    Cheers,
     
  4. Midnight

    Midnight Member

    Messages:
    48
    Location:
    North Yorkshire
    Thanks ceg that's put a few things into perspective.
    I was naively thinking that increasing the light and dosing would make the plants grow more vigorously and therefore "starve" the algae out of existence. Obviously not understanding that BBA and CO2 are inextricably linked I see now why that would increase the problem.

    With the solenoid valve and controller the PH is quite stable to within .02 throughout the day although usually drops overnight. I have adjusted the CO2 content gradually over the past few weeks i.e by lowering the PH setting from 6.8 to 6.6 and increasing the bubble count. Considering the KH is only 3degrees I was surprised to see the drop checker still showing a sea green colour. I will continue to lower it with the controller - a safety net as I am away quite often.

    If there were no fish in the tank I could presumably get rid of the BBA by simply increasing the the CO2 until the drop checker turned yellow. Although not fully understanding the relationship between the PH reading, CO2 content and other influences like bog wood, am I correct in thinking that the fish won't be affected by lower PH as long as the CO2 content is around 30ppm (i.e. lime green colour drop checker)?
     
  5. Stu Worrall

    Stu Worrall Forum Moderator Staff Member

    Messages:
    1,986
    Location:
    Flintshire, North Wales
    can you not just push up the KH with something like sera KH+? The PH controller will then put more co2 in to hold it at 6.6 or 6.8
     
  6. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Midnight,
    The odds are that you will continue to experience difficulty as long as you worry about pH stability at the cost of CO2 stability. The pH/KH/CO2 relationship in a tank is nonexistent. The reason for this is that there are other acids in the tank water which are not related to the Carbonic acid being produced by the CO2. Your pH controller has no idea where the pH reading is coming from and it cannot separate pH effects of the Carbonic acid from the effects of these other acids so in effect it is constantly reading a false high CO2 concentration level. You yourself reported that the dropchecker revealed that the CO2 level was lower than previously thought. This should have been an indication that the controller has no idea about CO2 levels because the one-and-only parameter it uses to determine CO2 levels is corrupt. The tank produces nitric acid, phosphoric acid and may other types of organic acids naturally and these acids destroy any fidelity of the pH reading. This is precisely why we use an uncontaminated sample of distilled water adjusted to a known KH value in the dropchecker - to isolate it from the tank water, so that it's pH reading can only be attributable to Carbonic acid and not other acids.

    If you believe nothing else, believe that algae cannot be starved. Plants require about 1000X more nutrients than algae so there is no conceivable way of starving algae without first annihilating the plants.

    A lime green dropchecker is nice but it does not tell the whole story. The BBA is a more accurate indicator. Remember that not only does the CO2 concentration level have to be adequate, but the concentration levels must be stable as well. If the concentration level fluctuates too much this affects the plants ability to use the CO2 and algae is then induced. Stable pH has absolutely nothing to do with stable CO2. You best bet is to forget about pH because neither plants nor fish care about pH or pH stability. Worry more about stable and adequate CO2 injection rates and good flow. This is why a simple ON/OFF schedule for the solenoid will work better for you. Pick an injection rate, turn the gas ON 2 hours before the lights go on and turn the gas OFF two hours before the lights go off. When lights go on dropchecker should be lime green or yellow (depending on your flow and distribution).

    Simplify you life by forgetting about bogwood, forgetting about pH, forgetting about KH and just concentrate on making sure that you have a stable and decent injection rate while not gassing the fish.

    Cheers,
     
  7. Ray

    Ray Member

    Messages:
    474
    Location:
    Switzerland
    This makes me wonder how much the ph in a typical tank fluctuates over a typical week assuming EI dosing and a 50% water change? If this fluctuation is substantial then just "dialing" the ph down until you have a nice lime green DC is simply not going to work - you are better off having a steady injection rate.

    But as we know, a "steady" injection rates is not 100% either - mine drops off when I swap in a new bottle of CO2 and then speeds up just before it runs out - both of which requires tedious manual intervention. Also after a water change my CO2 level is lower at the next "CO2 on" than normal, as without a w/c some CO2 persist from the previous day. It would be sooo good to automate all this.

    So which method gives the least bad fluctuations?
     
  8. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Hi Ray,
    Yeah, you definitely have a good point. I'm confident the controller can be set to a low enough pH target it can circumvent the effects of the tanks acids. The question is, will that value nuke the fish in that particular tank. There are many who use the controller effectively. It's important to understand the chemistry though. I use the tanks pH value as a means to an end - without being hypnotized by it, so for example I know through repeated measurements that generally (in my particular tank) a 6.2 pH gives me a pretty good CO2 saturation for my lighting level, but I don't blindly follow this number. I just use it as one of many indicators.

    Cheers,
     
  9. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    Having short lived CO2 fluctuations won't do any harm, ie when doing a water change or replacing an empty CO2 bottle.

    Strange you say that your CO2 flow rate fluctuates with new or nearly empty bottles. As long as this doesn't happen too much and doesn't last long then you should be OK. If it fluctuates over a week or so then yes I'd start to have concerns, but in all honesty with a good quality regulator it shouldn't change.

    My JBL reg never gets adjusted from one bottle to the next. I put a new pub bottle on and run it till it's totally empty without the bubble rate changing one bit.

    James
     
  10. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Hey James, that might in fact be the difference between the higher quality/cost (name brand) regulators versus the Asian knockoffs. :idea: I have the same problem Ray has when changing bottles out - the needle valve has to be closed a bit. As the bottle empties it has to be opened a bit. My high quality hand built welding regulator never had this problem.

    Cheers,
     
  11. Dave Spencer

    Dave Spencer Member

    Messages:
    1,389
    Location:
    N. Wales
    I am using a JBL regulator and one from Aquamas in Germany, and never have to adjust either when changing from bottle to bottle.

    The only thing I do make sure of is that the bottles aren`t allowed to drop to any significant value below 50 Bar, as I have had an occassion when the remnants of the bottle has dumped in to the tank in one go.

    Dave.
     
  12. Midnight

    Midnight Member

    Messages:
    48
    Location:
    North Yorkshire
    I was just planning to use the controller as a fail safe i.e so that the CO2 cuts off at some point whilst I'm away to avoid a disaster. I keep gradually lowering the PH setting to increase the CO2 content but using the drop checker (and the BBA) as an indication of the CO2 level/stability. After your advice yesterday I lowered the controller setting to 6.55 and this morning the drop checker was near lime green. However as I'm preparing to go off for the weekend now, I have changed 30% of the water and added new KH5 solution which will show blue for an hour or so.

    If I was around all weekend I would dump the controller and tweak the needle valve as you suggest in your drop checker article. As it is I aren't confident enough yet to just leave the CO2 running all day and shutting it off at night via the time switch. I will gve that a go when I have some time to monitor it for a few days. I'm also not confident with the Dennnerle regulator and needle valve, I seem to be adjusting the bubble count far more than James suggests I should.

    Taking Ray's point, I was thinking I can use the controller at a low enough setting to keep a stable CO2 content i.e if the magnetic valve stays open all day and the drop checker shows green all day the stability should be good - shouldn't it?
     
  13. Ray

    Ray Member

    Messages:
    474
    Location:
    Switzerland
    Ah, being a cheapskate I let it carry on until it stopped :oops:, but I was adjusting rate for the last 4 or 5 days. However, I just swapped in a new bottle on an Aquamas reg. and the flow definitely drops over the first hour or three. I know this because I don't touch the needle valve, just adjust the setting on the reg where I know what setting = what bps (saves a lot of counting) and the reading drops initially with the new bottle.

    Interesting because the above mentioned drop off caused 4 hours without CO2 & I've been watching out for BBA ever since - would you say that's not enough to induce it - that I'd need a few days of low CO2?

    I wonder if you could put the PH probe in a DC, or would the lag make for worse fluctuations than without? We need a DC with a semi permeable membrane and very low volume of liquid on the other side. Another idea I like for a super high tech tank is automatically turning banks of lights on and off as the CO2 concentration fluctuates - this is faster to take effect than just turning CO2 on and off.
     
  14. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    Can't see a day of low CO2 being too much of a problem as long as the rest of the time it is constant and stable during uptake periods. Takes plants much longer to shift their manufacturing processes.

    The semi permeable membrane and pH probe has already been thought of and made by Tom Barr.

    James
     

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