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KH2PO4

Per Rudi Danielsen

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Joined
13 May 2016
Messages
18
Location
Norway, Sandnes
Hi

I have 100 liter
I have used Jbl test kitt
Messured 0,3 PO4

I have now dosed with dry fertz into a can.

1 ml will be 0,0698 ppm

So i have dosed 20ml.

30min and 60min later i still read 0,3 ppm.

When can i expect to se change inn PO4 ppm

Rudi
 

dw1305

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UKAPS Team
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7 Apr 2008
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12,113
Location
nr Bath
Hi all,
Hi

I have 100 liter
I have used Jbl test kitt
Messured 0,3 PO4

I have now dosed with dry fertz into a can.

1 ml will be 0,0698 ppm

So i have dosed 20ml.

30min and 60min later i still read 0,3 ppm.

When can i expect to se change inn PO4 ppm

Rudi
It could be the test kit, or it may be that there really aren't any more PO4---- ions in solution. Often the amount of soluble PO4--- doesn't have much relationship to the reservoir of insoluble phosphate compounds. Keeping phosphate in solution is more problematic in harder water.

I'm not sure that trying to measure phosphates will give you any meaningful results, and it differs from NO3 etc in not being included in the water quality test results from your water company.

cheers Darrel
 

Per Rudi Danielsen

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Thread starter
Joined
13 May 2016
Messages
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Location
Norway, Sandnes
After reading and checking. Iam left with this.

1) JBL PO4 test kit dont work on KH2PO4 dry ferts?

2) The dry ferts have K in it but what else ???
Its not KNO3 or KCI powder.

Dont realy want to dose Ei style just because i cant test the water

Rudi
 

three-fingers

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Location
Scotland
The whole idea behind EI is that you don't have to test the water, so I think your missing the point a little ;).

You just add more than could possibly be needed, then do a 50% weekly water change to eliminate the possibility of too much of one substance accumulating over time.

Most aquarium test kits are not very accurate, so are a waste of time with regards to plant nutrient availability anyway.

What "dry ferts" are you adding? Surely you should know what is in it from the label or source you purchased from?

edit: Do you mean your "dry ferts" are just KH2PO4? If so, it has potassium (K), hydrogen (H), phosphorus (P) and oxygen (O). We are adding it for the potassium and phosphorus.
 
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Dont realy want to dose Ei style just because i cant test the water

Like previously mentioned dosing EI is a workaround for not having equipment that can measure certain water parameters accurately without spending thousands of pounds on equipment and even if you could the results can change pretty quick. It may say what's in the water but if its in a form the plants can use is a different matter. PO4 can react with Iron and precipitate out which is why we don't mix macros and micros together and the reason water companies add it to our tap water to prevent lead poisoning from lead pipes as well as corroding metal pipe fittings, they also make iron precipitate out so they can filter it from the water. Your test may be saying po4 is in there but maybe in a different state. Also the test kit is heavily reliant on you making the decision on what it's saying. Depending what mood you're in will affect the result, if you think you must have low po4 and in the right light your kit tells you that you'll say "I knew it" Plus the kit in some cases like the HAGEN one measures up to 1mgl from nothing so how many shades of blue are there and could you differentiate between them? The amounts involved are so small I don't believe a test kit would know the difference.
With EI the whole point is Tom Barr has worked out that it doesn't matter how much light and co2 you put in a tank the plants can never use more fertiliser than we put in so as such it's a starting point for us all regardless of what lighting or setups we have.

If you want to roll back po4 the best way would be to start at EI levels and very gradually reduce it over time until you see a bad reaction in the plants. The downside of this is algae could attack before the plants show signs so you add more and have plants that are feeling a bit under the weather and algae mixed with loads of nutrients. The algae is going to grab them first and the long soul destroying battle with algae begins until you can reverse the situation and believe me algae are better at the game because they are not as fussy eaters.

So it's up to you which route you take, with EI your belt and braces safe as long as you have good flow to get these nutrients to the plants. Some tanks with poor flow may need more to accommodate that.

I'm not sure that trying to measure phosphates will give you any meaningful results, and it differs from NO3 etc in not being included in the water quality test results from your water company.

This was something I looked into a while back having heard my tapwater was full of po4 and indeed couldn't get results from my water authority. I gave them a ring and unexpectedly someone rang me back who was extremely helpful, we even ended up talking about fishkeeping! I suspect it was a lab rat who doesn't get out the lab much and enjoyed seeing the end result of what they were doing and thought for once someone is interested :D so if you want them you can get them.

In my area (North West) the water authority added 0.94 mgl to the supply on average in 2016, generally speaking she said that they add 2000 micrograms per ltr in the UK or 2mgl. Either way it's not a great deal but on Hagen test kit would be off the scale. You can sort of accept there is some in there and take it into account when dosing if you could be bothered I suppose.
The World Health Organisation recommends no more than 5mgl should be put into water supplies but I'm not sure if that's something all water authorities adhere to. That being the case even if they did, which is unusual, you would just in EI parameters without dosing any after a 50% change with tapwater. It's fair to say though there is no evidence that po4 has any health implications above 5mgl. It's mainly to stop phosphate entering the water system and destroying local water course with eutrophy (spelt wrong, going from memory:rolleyes:) essentially promotes algae growth and increased plant growth which dies quicker than it can break it down>low oxygen>premature death to the water course.
For what it's worth the limit on no3 is 50mgl, Apparently this is to stop "Blue Baby Syndrome" where nitrate in the gut can turn back to nitrite and starve the oxygen. So unless the local water authority are up to no good the limits should be 5mgl po4 and 50mgl no3 which then brings me back to test kits when I hear people saying it's showing 75mgl out the tap.

I reckon anyone who has those parameters is in for a cheap hobby if high energy planted tanks are their thing. You could actually sell that in the lfs as "water for planted tanks" :rolleyes:
Forgot to say... I think that's where the phosphate and algae confusion comes from when you look round sites. In a tank with no plants po4=algae, In a tank with po4 and no other nutrients=algae and po4 in water courses = algae but in the planted tank with thriving plants not so.
 
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dw1305

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Hi all,
In my area (North West) the water authority added 0.94 mgl to the supply on average in 2016, generally speaking she said that they add 2000 micrograms per ltr in the UK or 2mgl. Either way it's not a great deal but on Hagen test kit would be off the scale. You can sort of accept there is some in there and take it into account when dosing if you could be bothered I suppose.
I think that is right somewhere in between 0.5 and 2ppm PO4--- is added. A couple of times I've used the ammonium molybdate / stannous chloride method to test other peoples tap water, and it has come out such a deep blue that I haven't been able to put the samples in the spectrophotometer. You would have needed to dilute the samples with a lot of DI water to get them on the standard curve.
That being the case even if they did, which is unusual, you would just in EI parameters without dosing any after a 50% change with tapwater. It's fair to say though there is no evidence that po4 has any health implications above 5mgl. It's mainly to stop phosphate entering the water system and destroying local water course with eutrophy (spelt wrong, going from memory:rolleyes:) essentially promotes algae growth and increased plant growth which dies quicker than it can break it down>low oxygen>premature death to the water course. For what it's worth the limit on no3 is 50mgl, Apparently this is to stop "Blue Baby Syndrome" where nitrate in the gut can turn back to nitrite and starve the oxygen. So unless the local water authority are up to no good the limits should be 5mgl po4 and 50mgl no3
Natural levels of PO4-- are really low. Because it is persistent in the environment it is estimated that, if we stopped adding phosphates to the ecosystem tomorrow, it would take a 1000 years to deplete it back down to background level.

The 50 ppm NO3 limit is still occasionally breached by some water companies, particularly in the SE of England, where the combination of low rainfall, intensive agriculture and large population all combine to make the water fairly nasty. Phosphate stripping plants have also been installed at sewage works etc.

cheers Darrel
 
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"Natural levels of PO4-- are really low. Because it is persistent in the environment it is estimated that, if we stopped adding phosphates to the ecosystem tomorrow, it would take a 1000 years to deplete it back down to background level."

Wow, it's amazing the damage we cause. I was watching something about Sellafield nuclear plant the other week which is just up the road from me
Apparently the waste there has a half life of one hundred thousand years! It didn't work the first time, we'll be clearing the mess up for eternity and now they want to build a new one where the old mess is. It's a bit like having a party, wrecking the house then just as you're finishing clearing up day anyone fancy another party :)

I found out about the po4 levels in my tap after going through the test kit dance some years ago. From what I read lately they are trying to get the levels added to tap water down so I suppose that's a step in the right direction.
A local Discus breeder warned me about high po4 and a test kit confirmed this. Little was I to know that test kits measure at really low values and what it was measuring wasn't much in the scheme of things anyway.
As for high nitrate it beggars belief. My understanding was you would only get levels higher than that if it was well water.

Ironically if you had these levels of no3 and po4 out the tap a 50 water change would still only be ei levels. So I guess people worrying about what comes out the tap is fairly irrelevant.
 

dw1305

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Hi all,
I was watching something about Sellafield nuclear plant the other week which is just up the road from me
Apparently the waste there has a half life of one hundred thousand years! It didn't work the first time, we'll be clearing the mess up for eternity and now they want to build a new one where the old mess is. It's a bit like having a party, wrecking the house then just as you're finishing clearing up day anyone fancy another party
I've been around <"Hinkley Point"> a couple of times. The present nuclear power station is an <"advanced gas cooled reactor"> and pretty safe, but the new one will be a <"pressurised water reactor">, and that certainly worries me more. I don't think nuclear fission can ever be a viable way of generating electricity, but it seems to be back in vogue.
Ironically if you had these levels of no3 and po4 out the tap a 50 water change would still only be ei levels. So I guess people worrying about what comes out the tap is fairly irrelevant.
This is why I'm always telling people on other forums that plants are the answer, they don't only deplete nitrogen, but phosphorus and potassium etc. as well.

cheers Darrel





.
 
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"I don't think nuclear fission can ever be a viable way of generating electricity, but it seems to be back in vogue."
Totally agree, it's just a sticking plaster which will delay the move to renewable 's even longer. Your not allowed to say that round our way though, an election has pretty much been won on it purely because so many people work there locally.

It has got me thinking though regarding po4. Makes you wonder how much we add to the environment. In most cases we over dose our tanks though laziness and the want to have a decent scape quick not contemplating that the majority of those ferts will end up down the drain and into the water system. I use my old tank water to water the garden but no real call for it this time of year up norf.

I think I'll start taking a look at my dosing. I was doing that anyway in the hope of lowering my tds to see what I can get away with but this has given me more incentive.
 

dw1305

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Hi all,
It has got me thinking though regarding po4. Makes you wonder how much we add to the environment. In most cases we over dose our tanks though laziness and the want to have a decent scape quick not contemplating that the majority of those ferts will end up down the drain and into the water system. I use my old tank water to water the garden but no real call for it this time of year up norf.
In the UK we add about 5kg Ha-1 year-1 phosphorus to the environment.

The largest source is from agriculture, with the PO4--- bound to soil particles and getting into the water courses via agricultural run-off. This is the abstract from Kleinman, Peter JA, et al. "Implementing agricultural phosphorus science and management to combat eutrophication." Ambio 44.2 (2015): 297-310.

In 2009, the UK population consumed 31 kt of phosphorus within their food.
UK food production relies on imported P, with net imports containing 113.5 kt P.
Crop production is 81% efficient; soil accumulation is estimated at 37.5 kt P/yr.
Losses to water total 41.5 kt P/yr, with 23.5 kt P within Waste water Treatment Works effluent.
Effectively recycling wastes such as animal manure and sewage sludge is an issue.


The really strange thing is that the phosphate we are using is a "fossil fuel", and there are likely to be shortages in the future.

There are more references in <"Can I mix....">

cheers Darrel
 
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So I guess my excess po4 dumped into the drain isn’t going to make much of a difference :D Interesting read though. "Optical brighteners in washing powders are less of a problem now, due to changes in legislation." Round our way we had another factory Marchon (Albright & Wilson) yeah, we're a dumping ground for any factories no other town wants :D They made Phosphate based washing powders. The houses surrounding the factory couldn't grow any grass on their gardens and the Seagulls, if they were to crap on your car and you didn't clean if off straight away it left the outline of it permanently burned into the paint work.
The factory closed a few years ago because a few people claimed against them and won which opened the flood gates for more litigation. Off they went to where ever they came from. There is a new housing estate built on the site now but before they could a couple of metres of top soil had to be removed and a layer of what looked like lime layered over then new top soil. I suspect that might have been to soak up all the excess phosphate that was left by the factory.

The new estate is still struggling to get grass on their gardens so PO4 isn't always good for plants :rolleyes: It's one of them places where 20 years down the line questions will be asked about whether the land was suitable for housing I reckon.
 

Per Rudi Danielsen

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13 May 2016
Messages
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Location
Norway, Sandnes
I bought new dry fertz from co2art and all is fine now.
My internett has contacted his supplier because he also cant do any test. And it would be wrong selling something no one knows what is

And thnx for all replies. God reading for a newbi
 
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