Understanding Water Test Results

[kayoss]

Hi All

I've had my tap and pond water tested at my local water board's laboratory and am a bit confused by the results!

The results I have are:

Ammonium as NH4 (mg/l) Tap = <0.04 Pond = 0.14
Nitrite as NO2 (mg/l) Tap = <0.008 Pond = 0.073
Chloride as Cl (mg/l) Tap = 33 Pond = >150
Total reactive Phosphate as P(ug/l) Tap = 375 Pond = 205
Sulphate as SO4 (mg/l) Tap = 48 Pond = 63
Hardness as Ca (mg/l) Tap = 126 Pond = 117
Total Oxydised Nitrogen as NO3 (mg/l) Tap = 27.9 Pond = >60
Conductivity @ 20C (uS/cm) Tap = 735 Pond = >1278
pH Tap = 7.4 Pond = 8

I added 0.6% salt about 3-4 months ago and did about an 70-80% water change a couple of weeks later to remove most of the salt.
Because of what appeared to be a persistent bacterial problem, I added CT to the pond a few weeks later and have continued to do regular filter cleaning and water changes since - at what I thought was at least 10% a week, but looking at the conductivity I think I've over estimated the amount I've been changing! )

My question is, is the Chloride (Cl) reading likely to be the remaining salt that I added or possibly some remnants of the Cholramine T treatment? Also, if it's some form of Chlorine, could this still be affecting the bacteria colonies in my bio filter and preventing them from being as effective as they ought to be (I have about 500litres of aerated K1 for a 5000 gallon pond).

Any advice greatly appreciated.

BTW, since getting the results I've done a 95%+ water change (koi literally flapping on their sides in the bottom of the pond) to get rid of as much polution as possible, but the koi still have very red fins and don't look as happy as I'd like them to be!

Cheers

Bob

[Manky Sanke]

Bob,

Without knowing the precise details of the test they used to check for chloride, I couldn't say with 100% certainty but in all probability, yes the chloride they found has mostly come from the salt (sodium chloride) that you added.

There might be a small residual from the chlorine in the chloramine T because chloramine is very long lasting but aeration and some sunlight should have eliminated that.

It isn't surprising that the test still found greater than 150 mg/L. The original salt concentration would have been 6,000 mg/L which you reduced to 1,500 mg/L by a 75% (ish) water change then to 1350, 1215, 1094, 984, mg/L and so on with each 10% water change so you can see how slowly it would have come down. It would have taken the original 75% plus 22 x 10% changes to drop below 150 mg/L.

Will the chloride in the water have affected your bugs?

Chloramine T has a chlorine content that would kill a biofilter but it isn't long lasting so, if you isolated your filter during the treatment, that won't have done the colony any harm. The residual when you restarted the filter might have been the final nail in the coffins of the old weak ones but that would have made space for new ones to grow so if anything that would be a good thing.

The chloride that was locked up in the salt treatment can't hurt the bugs but salt water isn't the natural environment for freshwater bugs which is why we use it as an antibacterial treatment. It dehydrates them to death. Bugs in a biofilter have some protection because they are in a biofilm which shields them from the full effect which is why people who salt their ponds kill free floating bugs but don't immediately kill their filters and you've been diluting the level ever since so I doubt you have damaged you biofilter.

Want the bad news? Well its not that bad, I'm just having some fun with chemistry!

If you have used a liquid dechlorinator based on sodium thiosulphate when you did those water changes you've been making salt! Not in great quantities, it takes two atoms of chlorine (plus the sodium thiosulphate) to make two molecules of salt so, in layman's terms, you could say that every atom of chlorine ends up in a molecule of salt and stays in the pond indefinitely, only being reduced by water changes, when you go and make more salt by adding more dechlorinator

In reality, the level of salt created by using a liquid dechlorinator will only be very small and can't ever slowly build up so you don't have to worry about Duncan or me coming round and throwing bricks through your windows for continually putting salt in your pond

[kayoss]

Hi Syd

Many thanks for the info mate - but the telephone chat was really necessary to make sure I understood it properly!

Cheers

Bob

[Manky Sanke]

Bob,

With the water changes you've done, especially the near 95+% water change, if it was due a water chemistry or water pollution problem, you would have eliminated it at least for a while until the pollution/contamination built up again.

I can give you the details of a company in London where you could send or take a water sample and they can test for just about anything you can think of but each test will be individual and there is a cost per test. But if an almost total water change didn't provide some improvement for a while at least, I would be thinking along the lines that you have eliminated anything to do with the water as the cause so a health problem, possibly a systemic bacterial problem seems to be more likely.

Why not post the symptoms on here and see if anyone has encountered this before or can offer any advice?

[kayoss]

Hi Syd

Sorry mate, I should have made it c;ear in the original post, but I'm still stressing about the symptoms that caused me to start this thread http://www.koiquest.co.uk/forum/viewtop ... 29&t=11784

The water tests are the latest route I've taken to try to resolve the red fins and lethargy I referred to then. Still get the occassional whate faecea, but not so often.

Cheers

Bob

[ageinghippy]

Hi Bob,

Going back to your original problem with your nitrite reading, have you considered using a tower/shower filter??

On another site, koimag I think, there were quite a few people having long term trouble with highish nitrite readings, and one of the posters recommended that they should get themselves a tower filter, and that it should be used it in conjunction with their existing filters.

Within days, the nitrite ceased to exist. (apparently), and everybody was happy again.

Anyway, it might be worth a try?

Chris (another one)

[kayoss]

Hi Chris

many thanks for taking the trouble to post.

I suspect that I saw the same post on koimag, was it the one recommending alfagrog?

Anyway, I already had a TT running with biomaze, but because of the results others seemed to be getting with Alfagrog, I added a mixture of grog and Blagdon ceramic to one of the tiers - that was a couple of months or so before I had the water tested!

It's really wierd! None of the koi appear to be getting any worse or significantly better. They seem to take it in turns to lie on the bottom and have red fins, but they're all pretty lethargic and don't even rush to the food at feeding time - even if I miss a couple of feeds out!

Thanks again for the suggestion

Cheers

Bob

[Gazza]

Hi Bob,

This sounds strange and could it be anything to do from the new build somewhere perhaps

[kayoss]

Hi Gazza

Must admit that the thought had crossed my mind too!

However, when I thought about it a bit more, if I did have styrene leaching from the fibreglass or any other chemical contamination, I'd have expected to see an improvement after the big water changes (75-80% first time and 95%+ last time) - even if the improvement was only temporary!

Think I'm going to end up having to get a couple of fish off to a lab for tests!

Cheers

Bob

[ageinghippy]

Hi Bob,

Before you go out to your pond asking for volounteers, have you/can you test your fibreglass to make sure it has cured properly?? A wipe of the surface with some acetone on a clean cotton cloth is all you need, if the cloth stays clean, you`re good, if any colour comes off, you`re not.

Obviously in a perfect world, you would empty your pond completely, dry the walls and floor, then go over every square inch with an acetone cloth to do your test, but even testing some fibreglass from above the waterline should give you a guide to how well it`s cured.

Chris

[kayoss]

Hi Chris

Thanks for the tip, and well worth a try - but no colour coming off the small amount of glass I can reach.

I suppose that should be worth a , but I'm still and instead!

Any other suggestions greatly appreciated guys.

Cheers

Bob