Understanding my water supply report?

Discussion in 'Water Chemistry' started by Steve Smith, 4 Mar 2009.

  1. Steve Smith

    Steve Smith Member

    Messages:
    4,428
    Location:
    Leamington Spa, UK.
    Hey all. I'm looking for help understanding my tap water supply, in relation to my GH/KH and in relation to dosing EI (should I be adding Potassium/Magnesium Sulphate etc).

    My water report is as follows:

    [​IMG]

    Can anyone help me decipher this?

    Thanks in advance! :)
     
  2. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    You dGH is 9.7 but what the calcium and magnesium levels are in that are anyones guess.

    Nitrate is 22.6 mg/l which isn't too bad.
    No mention of potassium
    Salt (NaCl) levels may affect some sensitive plants, but most should be fine.
    Iron is ok at 1ppm
    Copper is low
    Not sure about lead.


    James
     
  3. LondonDragon

    LondonDragon Administrator Staff Member

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  4. Steve Smith

    Steve Smith Member

    Messages:
    4,428
    Location:
    Leamington Spa, UK.
  5. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    From first post GH = 9.7 = 69.8mg/l Ca

    From water report Hardness (Total) as calcium = 68.25

    This either means that all the GH is calcium or (much more likely) they just quote the GH as Calcium which is why the two figures are pretty much the same.

    Thames water do exactly the same and don't have any mention of magnesium even though they name a whole list of compounds most people have never heard of.

    James
     
  6. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    LD,

    Your dGH comes from the CaCO3 figure which is 282mg/l or 15.8 GH

    But again this figure for the total hardness is quoted as CaCO3 so is impossible to work out how much of it is made up from calcium or magnesium.

    James
     
  7. Steve Smith

    Steve Smith Member

    Messages:
    4,428
    Location:
    Leamington Spa, UK.
    That's a tad anoying! Thanks for the interpretation James :)

    So I assume I'd be fine just dosing Magnesium as per EI ppm's?
     
  8. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    What are the EI recommended amounts. I'd just add 5-10ppm weekly to your tank and see how it goes.

    James
     
  9. LondonDragon

    LondonDragon Administrator Staff Member

    Messages:
    10,298
    Location:
    London
    Hi James, looking at my water report, which values do I use?

    PCV? Min? Mean? Max? Total??

    Just wondering how to read this thing hehe

    Many thanks :)
     
  10. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    PCV is Prescribed Concentration or Value. ie the prescribed limit allowed
    Total is the total number of samples that were taken to be tested.
    Min is the lowest figure they got.
    Max is highest reading they got.
    Mean is the mean figure of the samples. A bit like the average but not quite. It this figure that is best used to look at the amounts.

    HTH
    James
     
  11. chris1004

    chris1004 Member

    Messages:
    565
    Hi James /all,

    I've read this thread with interest after a couple of discussions we have had with regard to water quality recently specifically this one:-

    viewtopic.php?f=11&t=4971

    I would expect that I have similar water to that of 'londondragon' and although challenged when I read his area water report (due primarily to being a thick trucker, LOL.) I couldn't help but notice that there are levels of chemicals present which were quoted in the aformentioned link. So how much of each one is too much for our fish? and could they build up in our tanks over time due to evapouration? What happens to disolved levels of lead, murcury, solvants, refrigerants, arsenic, etc . Are they taken up by the plants and utilised by them? Do they enter the food chain within our tanks? Is Ro water completly devoid of all these impurities?
     
  12. chris1004

    chris1004 Member

    Messages:
    565
    The above were not supposed to be rhetorical questions guys.
     
  13. Ed Seeley

    Ed Seeley Member

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    3,262
    Location:
    Nottingham
    RO water has lower levels of all these things. The TDS is the measure of everything dissolved in the water (with the inaccuracies we have discussed before! :lol: )

    Will they build up in the tank? Well they shouldn't as your water changes should be of sufficient size and quantity to prevent this. You'd need huge evaporation, topped up with tap water and next to no water changes for this to happen (possibly some El Natural tanks...?) I'm sure plants and fish will take them up but as they're in such small amounts they aren't going to be a problem IMHO.

    In koi keeping one of the measures used to test your water is the TDS differential. Koi are fed heavily and prefer soft water (down as low as 30ppm) and so by measuring the difference between the TDS of the pond (which will rise as the waste and other dissolved items build up in between water changes) and the TDS of the incoming, fresh water you can see whether your water changes are enough to keep the TDS differential down. In a planted tank you could use this to check that too, but you would need to take into account the huge affect on TDS that adding ferts to the water has! That would blow any difference to the TDS due to the evaporation out-of-the-water IMO.

    Basically I wouldn't worry about it and certainly wouldn't advocate using RO water for this reason!
     
  14. Themuleous

    Themuleous Member

    Messages:
    4,126
    Location:
    Aston, Oxfordshire
    I've been looking at my water report recently, and I have to say its rather worrying! Apart from the usual elements, there is a huge long list of other things that are in my water, including several herbicides!

    Does anyone think these levels are high enough to affect my plants?

    waterreport.jpg

    Cheers

    Sam
     
  15. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

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    Location:
    Chicago, USA
    Hey Sam the units of those values are in micrograms per liter, not miligrams per liter so they're in parts per billion, 1000X lower concentration than our familiar parts per million (ppm). Furthermore the numbers are two to 3 decimal places to the right so in some cases that's parts per trillion, which is 1,000,000X lower. I'd say they're pretty low numbers mate.

    Cheers,
     
  16. Themuleous

    Themuleous Member

    Messages:
    4,126
    Location:
    Aston, Oxfordshire
    Thanks Clive :) That's pretty much what I had thought, but I thought it was worth an ask all the same, especially when I discovered that some of them were herbicides! Shame, it would have been useful and easily fixed problem had it been the reason for all my plant woes.

    Sam

    EDIT - just to pre-warn yo,' you'll probably get yet another PM in a week or so, once the uber high CO2 has had a chance to work, no not as the case may be (and as I suspect) ;) :lol:
     
  17. chris1004

    chris1004 Member

    Messages:
    565
    Sam, I regret our slight altercation on the earlier thread (you know the one) as I don't wish to fall out with anyone so hopefully we can just leave that behind us and move on.

    I have to admit that the above is pretty much where I am at as I simply don't understand what many of the elements that are listed are, or how dangerous they can be to my fish. Sure copper, lead, murcury and the like are self explanitory but many of the rest go straight over my head. As for the numbers that Clive has just pointed out I didn't realise they were so small.
     
  18. Themuleous

    Themuleous Member

    Messages:
    4,126
    Location:
    Aston, Oxfordshire
    Me too, Chris, so no worries at all completely forgotten :)

    I'm glad I'm not the only one who find all this rather confusing! Thank goodness for the likes of Clive and James who are there to reassure us all that its rarely anything to worry about :)

    Sam
     
  19. chris1004

    chris1004 Member

    Messages:
    565
    Learning all the time and really enjoying the experience and the results in my planted tank in my living room.

    To be honest it is dawning on me that I am overly paranoid when it comes to water quality. This has been conditioned into me through years of keeping various delicate species including discus and seeing as I have all the kit as it were I don't see a reason to alter what has been successfull for me so far. But at the same time I am starting to realise that it is not strictly necessary either, and certainly not at all for the hardier bread and butter type of fish commonly found in LFS or the hard water loving species such as african cichilids or fish from brakish water.

    The monitary value aside I am gutted if I lose a fish especially if its through my own fault and could have been avoided which to be honest has happened in the past and the feeling of guilt and the loss of a cherished pet affected me badly afterwards for quite a while, which is another reason for my paranoia and why nothing but the very best quality water is good enough for my fish now.

    Being challenged when it comes to chemistry I do take solace in relying heavily on what I consider to be a 100% foolproof and safe method of using reminaralised RO water for my softwater loving fish, but from what Tom Barr said in the previously highlighted thread with regards to most of the 'nasties' being removed by the carbon element of the RO filter I am considering reconstituting using the water post carbon filter and saving a few quid on the remineralising salts. Still a bit nervous about doing it though even though I don't doubt the advise that I have been given.

    My main point for concern is that if the carbon filter removes all the elements both good and bad indescriminatly that are in my tapwater, there would now be a defficiency of the good elements that have been removed that are required by both the fish and plants (as I understand it). Aswell as adding both KH and Gh to my Ro water my remineralising salts also reconstitute the water with the other elements that are required (so it says on the tin). I currently use 'Denerle ReMineral+' which according to the instruction pamphlet that you get with it contains, calcium ca2, magnesium, sodium, potassium, hydrogen carbonate, sulphate, chloride and trace elements of boron, flouride, iodine and others besides so effectivly 'cherry picking' the chemical makeup of the water utilised within the fishtank.

    So it appears I have a choice of putting up with the very low levels of elements which I don't understand wether they are desirable or not and in what quantities they can become a problem, reconstituting with water devoid of all elements both good and bad or trusting a chemist to get it spot on.
     
  20. Themuleous

    Themuleous Member

    Messages:
    4,126
    Location:
    Aston, Oxfordshire
    Haha :lol: this is exactly what I'm thinking of doing in my 4ft just to rule out the possibility of there being contaminants in the water, not that I think there are but as you say means I can get it spot on :)

    Sam
     

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