a few beginer queries

Discussion in 'General Planted Tank Discussions' started by fishgeek, 20 Jul 2007.

  1. fishgeek

    fishgeek Member

    Messages:
    117
    Location:
    west sussex
    not being a planted tank person, many of the posts on here lead me to more questions than understanding

    i have never subscribed to any website, so i dont have all the barr report information that some of you have read

    i see anacroynms are used and again i dont know these

    now for my questions

    when measuring CO2 levels in water i see that there is talk of a drop method? can some one explain what this is?
    i dont measure mine as i have some doubts about the validty of pH and kH tables , especially in tanks like mine where i know that peat amongst other things is altering my acidity not just dissolved carbon dioxide forming carbonic acid

    fertilising? do you all use the estimative index? i read a bit about it a will back and sounded a bit like everything added in excess and regular water changes leads to a nice equilibrium..( i am simple, amnd simplifying a lot) now i could be very wrong , it's just that seemed quite wasteful?!

    CO2 again, when plants are pearling is that an idication that prehaps more C)2 is being added than is neccesary or have i just read something and got the wrong end of the stick.. ie is there a maximum growth rate or if nothing is limiting will plants just grow faster and respire faster so pearling is an indication of fast grwoth...

    the talk about fertiliser agents , i use chempal trace elements mix from the local nursery.. still on my first 500 gram box and i though it was great value
    i have high phosphate in my tap 2.5mgs- 5mgs with a hagen test kit .. i have been reading and trying to understand the high phosphate water query response's , but as above cant rea the links
    what other materials dou you guys use
    what test kits do you recommend for checking iron levels etc or do those levels not get checked?

    i'm sure there are heaps more
    thanks andrew
     
  2. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    pH and KH tables can often be very inaccurate due to buffering capabilities of other substances like peat, bog wood and phosphates to name a few. This will throw the CO2 calculation out as it is only designed to work with CO3 and HCO3. According to the pH/KH tables my CO2 levels are over 100ppm.


    No there are many different ways to fertilise a planted tank but Estimative Index is by far one of the simplest as it requires very little knowledge to dose it. The only complication is CO2 which is where most people tend to go wrong because of the difficulties in measuring it. It could be regarded as wasteful I suppose but the materials used are so cheap and last a long time that this isn't really an issue.


    Pearling is caused by photosynthesis and plants giving off mainly oxygen as a waste product. The quicker they photosynthesise the more O2 they produce. This is controlled mainly by light but also by limiting a nutrient required by a plant. CO2 just has to be available at a good level for plants to be able to use it. Adding more beyond this point won't make too much of a difference and will not create more pearling. Plants adapt to CO2 levels by adjusting the amount of rubisco which takes time. This is the reason why plants don't like fluctuation CO2 levels. In a non limiting system plant growth is controlled by light. More light means faster growth and more pearling but there is a point at which plants can't grow any faster.


    I used to use the Chempak chelated traces as well - very good I found


    Don't trust what PO4 and NO3 test kits read unless you calibrate them first. They can be miles out at times. Generally high PO4 isn't a problem.


    Potassium nitrate
    Potassium phosphate
    Potassium sulphate
    Magnesium sulphate
    Chelated traces


    I like the Hagen ones best, but don't tend to use test kits very often. Forget trying to measure iron. Kits are so unreliable due to different iron states and if it's chelated or not. There's no real need to measure.


    Fire away

    James
     
  3. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,937
    Location:
    Chicago, USA
    HI Fish Geek,
    To keep things simple the drop checker is small vessel placed inside the tank which holds perhaps 1/2 teaspoon of water. A reagent is added to this water which measures pH. As the pH of the vessel’s water falls (becomes more acidic) the color of this water changes from blue (more alkaline), to green, to yellow (very acidic). Ideally, when the color is green this indicates that the optimal useful amount of CO2 is dissolved in this sample water. You can see typical drop checkers here:

    http://www.aquaessentials.co.uk/index.p ... op+checker

    As you can see, this funnel shape facilitates the ability to invert the vessel and to place it inside the tank while trapping a small amount of air. With the funnel opening facing down this trapped air isolates the liquid in the vessel from the tank water, however, as you inject and dissolve CO2 in the tank water it then also finds its way into this bubble and then dissolves into the vessels water. At some point equilibrium is reached between the CO2 concentration in the tank, the concentration in the bubble and the concentration in the vessel’s water. The reagent changes color as the carbonic acid content of the vessel’s water changes. I guess that since you mentioned pH/kH tables you are aware of the relationship so it should be no surprise that the water in the vessel should be composed of DI/RO (De-ionized or Reverse Osmosis) water adjusted to a kH of 4 to avoid the uncertainties caused by other buffers being dissolved in it. kH 4 water is now being sold but you can make your own. Essentially, with this water the pH/kH/Co2 table become relevant again and at around 30ppm dissolved CO2, the reagent turns green due to a pH of 6.6. My numbers may be off but this is the general principal. Origin of the term "drop checker"? I can't imagine it's anything more exotic than the fact of adding carbonic acid to the reagent water causes the pH to drop.

    You should subscribe to the Barr Report as it’s money well spent ($13 per year which is peanuts) The subscription fee will give you access to various articles which address these very same questions. You can browse the site in any case for threads. The first step is to read, read, read and then when you’re done read some more.

    Not everyone uses EI and those that do often adjust it’s use for their particular situation. You should not think of EI as some kind of dogma or requirement. It is a method of ensuring that there is always sufficient concentration of nutrients to provide growth, With the advent of more powerful lighting we have seen that this light is the motor which drives plant metabolism. To use the motoring analogy, imagine a car on the motorway moving at 100mph. The plant is the car and the light is the motor. What would happen if most of the engine oil were consumed? What would happen if the petrol level dipped to the “E”? Think of the effects of the loss of transmission fluid, brake fluid, tyre tread on the performance of the vehicle. None of these losses can result in better performance. You might try putting in just enough petrol or oil to get you to the next station but what happens if you got the levels wrong? Wouldn’t it be better to always have a full tank, full oil, full tyre tread etc? Yes, it might cost a bit more and could be considered “wasteful” to replace the tyres before minimum tread but consider the consequences of miscalculations at 100mph. The same consequences apply in your tank. When you deplete a nutrient that the plant required for top performance. The equivalent of a motorway crack-up in your tank is poor plant health accompanied by virulent and persistent algal blooms. Most EI devotees find that “wasting” a few grams of powder is preferable to the consequences.

    CO2 – As plants consume light and nutrients they “exhale” Oxygen. A the water becomes saturate with O2 no more O2 can be dissolved into solution and it comes out of solution as in gaseous form. This is called pearling which has become some sort of Holy Grail or Aquarist Nirvana. You should think more about plant growth rate. For example if the water temperature is very high such as found in a typical Discus tank the water has less ability to hold O2. Such a tank may pearl more readily than another tank kept at a lower temperature, yet the plant growth in the tank with the lower temperature may actually have better growth so pearling should not have the priority that it seems to have.
    Fertilizers – I’m not at all familiar with trace mix you mentioned but really there is not a tremendous amount of difference in the various mixes. The important thing is that you dose the proper concentrations and at the proper frequency. You didn’t mention whether you dose N, P or K but if not you will need to. These are top priority nutrients and are referred to as “Macro” nutrient since they are typically dosed in relatively large quantities the chelated traces are to plants what vitamins are to us.
    The phosphate discussion you mention became complicated because we are all still trying to interpret what we can physically see in our tanks within the context of the things that we can’t see. This is another reason EI is so useful. In fact the original poster of that thread was concerned with excess just as you mentioned that you were concerned with wastage. In fact EI was not the result of brainstorming. It was developed by someone who discovered, through his profession of working with water weeds and algae that excess nutrients doesn’t cause harm but that nutrient deficiency always causes harm. His conclusion was therefore to dose in a manner that never results in nutrient deficiency. If you follow this principle an if you never worry about wasting or exceeding you have a better chance of avoiding trouble.

    Test kits – In my opinion – Generally wasteful and irrelevant. I was once enslaved by the allure of test kits. I would pretend to be a scientist. I even completed the fantasy by wearing a white lab coat. I thought I would have an accurate picture of my tank parameters and that my plants would bask in the glory of nutrient bliss. It was a disaster. I was like a refugee as I mindlessly immigrated from one lame test kit to another, each giving more pathetic results that the previous one. I used fantasy concentration levels to calculate fantasy ratios and it was as if I were at the horse races. Some days, if my test kit was feeling good, I would score big. On other days, if the test kit hadn’t slept well, I would be the (no-so-proud) owner of an algae farm. Again, EI comes to the rescue in that you no longer need to test for nutrient concentration because you know that the concentration is sufficient. Who cares what the actual values are? I admit though that I always like to know pH, hardness, and more importantly, TDS (Total Dissolved Solids). These are parameters whose absolute values I feel are relevant to both plants and fish. I bought the Hana Pocket Combo meter which measure pH, temperature and TDS. It is supposedly accurate to within 0.01 pH (yeah, sure). As long s it generally agrees with my drop checker I’ll believe it. I find it very handy. A kH test kit isn’t too bad but I constantly attempt calibrations. For example, if I buy a 4 dkH water I make sure that the kit returns that value when I test. If I have a DO water sample the test must return a zero reading. If you want to talk about wasteful just check the prices on some of these kits. I’d rather use that money to buy more plants. Remember the drop checker also uses a reagent from a CO2 test kit. This is just another pH test kit though, in actuality masquerading as something more amazing.

    Apologies for rambling. It also just dawned on me that if you don't drive, the automobile analogy may have been a complete waste of time. In any case let us know if we can clarify anything else.

    Cheers,
     
  4. Dave Spencer

    Dave Spencer Member

    Messages:
    1,389
    Location:
    N. Wales
    BoyuCO2.jpg

    The purpose of the drop checker is to give a good indication that the tank CO2 levels are running at 30ppm. It is done by adding a few drops of Bromo Blue liquid to the bulb on the left of the dropper ( I actually use the drops from my Nutrafin Low Range pH test kit). Then you need to add a few drops of reference solution at a carbonate hardness of 4dKH, which is basically RO water with some BiCarb added until 4dKH is reached. The 4dKH reference solution is pure, without any unwanted influence on its pH, unlike using tank water, so adding the test drops to the solution we should see a dark blue colour (mine went beyond the upper colour scale of pH 7.6 on my Nutrafin chart).

    When the dropper is fitted below the water level in the tank, an air gap is trapped between the tank water surface and the reference solution. What happens now is that the amount of CO2 in the tank water will, over the period of an hour or two, equalise with the CO2 in the dropper air gap, and thus affecting the reference solution. The colour of the reference solution should change from blue to green, with green corresponding to a pH of 6.6 on the Nutrafin chart. Correlating a carbonate hardness of 4dKH against a pH of 6.6 and we get a CO2 level of 30ppm. If the solution remains blue then CO2 levels are too low, and if it goes beyond green and turns yellow then CO2 levels are too high.

    It is possible to make the 4dKH reference yourself, if you have the means:

    Add 6g of pure Sodium BiCarbonate to 5l of RO water to give you a solution at 40dKH.

    Mix 10ml of this solution with 90ml of RO to give you 1l of 4dKH reference solution.

    Regarding the issue of plants pearling, I always thought it was the result of rapid photosynthesis and the fact that O2 is not particularly soluble in water, as opposed to the water becoming O2 saturated.

    Dave.
     
  5. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,937
    Location:
    Chicago, USA
    Hi Dave,
    Yes of course you are right. 100% O2 saturation is not a requirement for pearling and yes O2 is not particularly soluable in water. Pearling is an indication of photosynthesis but my point was that good plant growth was the first goal and that trying to optimize a tank for pearling by using the amount of pearling as a parameter is not really the best way, especially for a beginner. I think a better approach is to focus on being systematic and disciplined in the dosing and CO2 application as well as with the lighting. I think one needs to develop observation skills to be able to "read" the plants and to understand signs of nutritional deficiencies etc. Scanning each plant and noting how rapidly is that new leaf emerging? what color is it? How does submerged growth differ from emersed growth? What is normal appearance for that species? How to recognize when it's failing? There are so many more profound things happening in the tank than just pearling that I feel it has become almost superficial. Yes it is lovely to see but I feel one shouldn't get hooked on pearling.

    Cheers,
     
  6. Graeme Edwards

    Graeme Edwards Founder Staff Member

    Messages:
    1,161
    Location:
    Wirral/Chester Cheshire.
    I wouldnt class my self as a begginer as such, but this thread is very interesting.
    I like the idea of makeing my own 4dKH solution. Thanks for that Dave.

    Can you tell me and fishgeek how much 4dKH solution goes into the drop checker? How much regent to the amount of 4dKH inside the drop checker, what regent should be used? And where can we obtain it.

    Cheers pal.
    Graeme.
     
  7. Dave Spencer

    Dave Spencer Member

    Messages:
    1,389
    Location:
    N. Wales
    No probs Graeme,

    I first read about using 4dKH on the Barr Report. What I do is half fill the bulb of the dropper with reference solution, and then add the drops of indicator to taste really. Adding more indicator will give a deeper colour, and less will give a more translucent look (I normally add about two drops).

    You need Bromo Blue as the indicator, because it is the one that covers the pH range we are measuring. Fortunately for me, I already had the Nutrafin pH test kit to hand. I replace the liquid in the dropper every three or four weeks.

    I work at a power station, so I have the means to make the 4dKH accurately. I was going to make some more up for if/when George`s BBQ happens, as I have given away virtually all of my current batch.

    ceg4048, you make a lot of good points about using plants and fish as the indicators for what is happening in our tanks.

    Dave.
     
  8. Graeme Edwards

    Graeme Edwards Founder Staff Member

    Messages:
    1,161
    Location:
    Wirral/Chester Cheshire.
    Thats cool Dave, seeing as we may be car sharing down to George's maybe you can slip me a bottle * cough cough*.

    Do you use the NutraFin ph test kit for the Bromo Blue?

    Cheers.
     
  9. fishgeek

    fishgeek Member

    Messages:
    117
    Location:
    west sussex
    thank you all for taking the time to type such involved and useful answers to my queries

    a few more is the 4 kH just an arbitary value?
    i take the situation to be that by using a drop checker with a known kh value that is only being affected by products that can diffuse across the buble chamber(ie this gaseous content of tank water) that we are removing the spurious tannic acids etc that can make a kh/ph table inaccurate

    i think i actually have an old plastic drop checker that came with my jbl system... it has only just now made sense to me .. i guess i never got the bit about a standardised solution..



    right so prehaps i should be looking at ensuring my light is better? i have 3 4ft tubes(t8?) over approx 200litres of water
    a combination of triphos and daylight..
    and then prehaps adding some poatsium nitrate to aid growth.. that seems bizzare to me, adding nitrate , i have always been educated to eliminate it...

    going back to light
    i was looking at plain old grolux and household full spectrum bulbs .. the lumens they emitted seemed to be much less than the claims on packaging for aquarium models.. is that genuine? or have i gotten muddled here

    i thought that most bulbs were compatible with plant growht, as long as daylight spectrum(5500-6500 k) and that more lumens were better

    thanks again
    andrew
     
  10. SuperColey1

    SuperColey1 Member

    Messages:
    2,668
    Location:
    Lincoln UK
    4dKH

    I thoug
     
  11. Dave Spencer

    Dave Spencer Member

    Messages:
    1,389
    Location:
    N. Wales
    You are probably right Andy, but we call it RO at work even though that is only one of the purification stages. The final product comes out at a conductivity of 0.002microSiemens/cm, which is pure enough water to be used as an insulator for high voltage motors.

    I forgot to mention that my indicator usually takes about two hours to start indicating the right CO2 levels.

    Dave.
     
  12. SuperColey1

    SuperColey1 Member

    Messages:
    2,668
    Location:
    Lincoln UK
  13. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,937
    Location:
    Chicago, USA
    Glad to help I'm sure I can speak for the other posters in saying I wish someone had taken to time to help me figure some of this stuff out when I started.

    Yes you have figured out the drop checker. Can you see that if you put tank water in the checker, instead of a known calibrated water sample, you would have exactly the same inaccuracy as using the pH/kH/CO2 table from readings taken from the tank? One less thing to buy if you've got one. I would be willing to bet it works as good as the contemporary Gucci models selling for 10 times the price (yours probably doesn't look as cool though). Remember to change the drop checker water and put new bromo drops in after every water change.

    The 4 dkH is arbitrary in a way but I believe that this pH/kH/CO2 combination is just enough to turn the bromythymol blue reagent to green at 30ppm CO2 which is nice and convenient. I think that JamesC hit it on the head when he noted that you should have a green indication by the tme the lights go on. As you see from the two posts above it takes between 1 to 2 hours from the time you turn on the CO2 for the drop checker to change from blue to green so either manually, or use a solenoid to turn on the gas 1-2 hours before the light comes on. Can you see why this is important? Remember the car analogy. the gas mus be up to speed by the time the light goes on otherwise for 1-2 hours you wil be "Limiting" photosynthesis by not having the proper CO2 concentration.

    OK, to the light; 200 liters is a 50 US gallon tank. I'm sure you've heard the rule of thumb called Watts per Gallon (WPG). Current wisdom is that less than 1.5 WPG is "Low Tech" and that anything higher than that is "High Tech" you didn't tell us how many watts the three bulbs are rated but lets say they are each 40 watts. that means you would have a total of 120 watts so your WPG would be 120/50 or, 2.4. If that's waht you bulbs are rated then you have plenty. tom Barr says that you ougth to be able to grow most weeds with 2 WPG. Some people like to use more light which is acheived with the higher output bulbs and ballasts, T5. Remember though that more light means more growth, faster metabolism and less margin for error. I would stick with what you have for now and as you become more adept you can increas the light. By that time you will understand the consequences.

    Triphos, Grolux, Schmolux - Plants (and algae) will adapt to any wavelength typically from about 400-700 nanometers (nm) If you bulb is rated at around 600 nm it probably looks pink when lit. Here comes more tedious info - plants use wavelengths in the red area for their photoreceptors - this is how they know whether they are in the shade or fully lit because red is lower energy. Someone interpreted this to mean that plants use red more than the other wavelengths so started marketing pink bulbs (Grolux). The Triphos energy spectrum has energy peaks at three locations, blue orange and red I think. You can see the spectrograph on the package - so three energy peaks - "Tri" get it?

    How would you like one less thing to worry about? Get the type of light that you think makes your plants look pretty, while being mindful of the WPG "rule" The plants will figure out how to use what you have. I'm guessing that the only frequency they don't like is green. I mean they reflect green and that's why plants look green. Your assumjption is accurate though. Most bulbs are compatible with plant growth.


    If you've ever taken a photograph under household flourescent bulbs you may have noted that the photograph has a green cast. That's probably because there is a green component to the wavelengths emitted by those tubes.



    Nutrients; You may be able to access this page without a subscription If you don't have a subscription you should buy one before you buy anything else - I doubt you will ever buy anything with the value per money in this hobby as a Barr subscription - 6 quid per year:

    http://www.barrreport.com/estimative-in ... -kits.html

    You really, really, really need to study that post. I'll reiterate that what you were educated about was not necessarily wrong because elliminating organic nitrates elliminates the "scum" excreted by the plants and animals in the tank. These oganic compounds can result in water discoloration and may possibly contribute to desease. What you will be dosing is INORGANIC nitrates, phosphates and minerals. There is no comparison.

    If light is the most important factor in plant growth, and if Carbon is the second most important then certainly Nitrogen, is the next most important. Dosing Patassium Nitrate as well as Potassium Phosphate gets NPK into the tank and are essential elements of EI. Here is a tidbit for you; Chlorophyll, the cell that executes photosynthesis, is made of predominantly Nitrogen. So when you start the engine by turning on you light, and then inject CO2, if you don't have enough Nitrogen it will be impossible for the plant to properly use these first two components because chlorophyll production/maintenance will be seriously impaired. The best way to get the plant sufficient Nitrogen is to dose NO3.

    In a few months you'll think back and won't even remember the bizare feeling, I promise...

    Cheers,
     
  14. fishgeek

    fishgeek Member

    Messages:
    117
    Location:
    west sussex
    the reason for the question about lights comes down to watts being a power consumption rather than output figure..i know we have an established 123 wpg rule.. but then there are 2 different size gallons... i guess it is just a rule of thumb

    wouldnt lumens or lux as output be better, and wouldnt more lumens per watt be better use of my energy to produce light... not that the plants care just me



    i have my solenoid on the same timer as the lights.. i guess iot needs to be on before and off ? before?

    thanks again
     
  15. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,937
    Location:
    Chicago, USA
    Yes, but life is complicated enough. Unless you have a submersible light meter there is no way to measure. Since no two bulbs have the identical efficiency how would you compare their outputs? As you've noted, it's just a rule of thumb and there is no need to get hung up on lumens. This is science but it doesn't have to be rocket science.

    As noted by JamesC your drop checker should be in the green (indicating 30ppm) by the time the lights come on. If not, every morning for an hour or so you will be CO2 limited and will be inviting algae. I think it would be better if you got a separate timer for the solenoid.

    Cheers,
     
  16. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    Lighting can be pretty complicated. Lumens are a very poor way to measure light output for plants as it is a measurement for the green part of the spectrum, ie what us humans are most sensitive to. Plants need red and blue spectrums which Lumens don't measure. Par is more accurate as this measure the entire visible spectrum but I don't suppose you'll find many manufacturers who quote these figures. Par still isn't perfect though as it still measures the green spectrum. Gro-Lux tubes which appear dim to us because they have little in the green spectrum actually appear bright to plants because the have large peaks in the red and blue spectrums. I use them to great effect but they'll need to be balanced out with a daylight type tube for a more natural looking colour.

    James
     

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