• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

EI dosing - PO4 salt don't show any trace of PO4

Hi all,
AverageWhiteBloke said:
Are people testing for po4 using the salt in pure water
Click to expand...
I made up the stock solution in DI water.
AverageWhiteBloke said:
I appreciate po4 tests are generally grossly out but there are also other things in tank water that could mask po4 in the tests possibly?
Click to expand...
No, if phosphorus is present as PO4--- ions, the kit will change colour.
dan4x4 said:
Macro fertiliser with 1 teaspoon of KH2PO4 - no phosphate present @ 0 PPM
Click to expand...
It is possible that the salt you were supplied with wasn't "mono-potassium phosphate" (KH2PO4), but it is also possible that it was KH2PO4 and that the PO4--- ions had come out of solution, and formed an insoluble salt.

If you have a precipitate in the macro solution? it is likely to be a phosphate compound. You could try acidifying the fertiliser mix (with "white vinegar"?) and then waiting a few hours before testing again.
dan4x4 said:
and got a reading of 1 PPM I assume this is coming from fish food and K2SO4 that I also add I also went on and tested the tap water which showed same reading. I only did a water change yesterday
Click to expand...
It won't be the potassium sulphate (K2SO4), but the fish food and tap water will both contain phosphate.

Most (all?) tap water in the UK has phosphate added, this is to ensure that any heavy metals (from lead, zinc or copper pipes are precipitated out) before they can reach the consumer.

cheers Darrel
 
Hi Darrel

Yeah its my fault, I know this but I'm an idiot and got mixed but between Potassium (K) and Phosphate (P). Honestly I would normally know this so i'm going to blame this cold I have LOLs.

I use tap water for my macro mix so its strange that it hasn't showed anything up on the test. Darrel is definitely right my water supplier does add phosphate to provide a coating on lead pipes on the water network - I know cos I work there and I asked a water quality scientist why. Although its no longer on my water quality report.

I have contacted the seller aquariumplantfood.co.uk and asked for a refund. I await a reply.

It'll be interesting to see if dosing makes a difference with this complete fertiliser I ordered today.

Just for the record here's my test result.
 

Attachments

  • IMG_6627.JPG
    IMG_6627.JPG
    977.2 KB · Views: 153
Hi all, at least I'm not alone in this thankfully as I was starting to doubt myself and think I might have really done something wrong.
There is 0 Phosphates in my tap water in Ireland and I have tested my salts with vinegar as previously already advised by Darrel.

I understand that there might be fluctuations because of the way the salts are created, but no PO4 at all in this salt when it is the main ingredient is bad to say the least.
If there is any danger of the phosphates dissolving because of some chemical reaction it should be stated on the package. I had problem from the start (and tested at LFS) so I'm quite sure I never had PO4 in the mixture.

I appreciate everyone's help and advise, thanks.
 
Last edited:
Yeah also anybody with these ferts might be worthwhile checking this out. Thanks ManDrawer for raising this. Consumer power!

I have a phosphate test kit spare if anybody needs it.
 
Hi all
After reading the thread and having trouble with GSA and stunted growth in my last high tech tank wich was not a complete disaster but was hard work to keep algae free. Today went and tested my macro solution in my lfs.There was no PO4 present in the solution.It is cristal clear and there are no bits that indicate any reaction with the other salts. I am using aquarium plant food dry salts too.Atm my tanks are all low tech and are also in not too bad shape .Maybe without CO2 suplement,the large wc and food I put in are able to provide some PO4.
Very usefull thread.Will buy new salts asap.
Thanks for the heads up.
All the best.
Regards Konsa
 
Just an idea, when testing in macro solution I would imagine N and P are in quite concentrated amounts, would this not throw the test?
 
Hi
I was not testing for accuracy.Any little value would have done.The lad in my lfs actually thought it was my tank water the PO4 test showed zero and he did NO3 too wich does indicate NO3 and changed colour.Then he started waffling that NO3 was a tad too high and if i have algae problems bla bla......I was not listening at that point.
I was testing amonia years ago with new amazonia and the colour of the test kit was soo strong that was not even on the chart the test came with.
So even in concentrated solution it should still indicate sth and change colour
Its a shame as while I was using branded ferts all was easy and once I swapped to dry salts it all became hard work.This was one of the reasons to go low tech.More slow growth and better times for reaction if I see sth that is not happening properly
Regards Konsa
 
Last edited:
dw1305 said:
Most (all?) tap water in the UK has phosphate added, this is to ensure that any heavy metals (from lead, zinc or copper pipes are precipitated out) before they can reach the consumer.
Click to expand...
Only in soft water areas is phosphate added. So as most of UK is hard water, chances of phosphate in your water is low.
 
I live in the north east most we tend to have mainly soft water.

Your water suppliers are able to tell you what the water hardness is for the area, however this may fluctuate. I know boreholes are where harder water comes from up here, some suppliers mix boreholes and reservoirs in order to cover demand and also to reduce cost.
 
Konsa said:
Hi
I was not testing for accuracy.Any little value would have done.The lad in my lfs actually thought it was my tank water the PO4 test showed zero and he did NO3 too wich does indicate NO3 and changed colour.Then he started waffling that NO3 was a tad too high and if i have algae problems bla bla......I was not listening at that point.
I was testing amonia years ago with new amazonia and the colour of the test kit was soo strong that was not even on the chart the test came with.
So even in concentrated solution it should still indicate sth and change colour
Its a shame as while I was using branded ferts all was easy and once I swapped to dry salts it all became hard work.This was one of the reasons to go low tech.More slow growth and better times for reaction if I see sth that is not happening properly
Regards Konsa
Click to expand...

I hear yah, anytime I have to leave for a few days (even with wife or kid helping) and come back I have to perform damage control with a big maintenance.. High Tech means High Work.

And many thanks for your feedback as well 🙂
 
Hi
Tbh not always high tech tanks are hard work.
I quite enjoy maintenance of my tanks and had some really easy high techs in the past.
It is just frustrating when even you are putting everything you have in maintaining them sth like that fert mistery is tripping you
Regards Konsa
 
Konsa said:
Hi
Tbh not always high tech tanks are hard work.
I quite enjoy maintenance of my tanks and had some really easy high techs in the past.
It is just frustrating when even you are putting everything you have in maintaining them sth like that fert mistery is tripping you
Regards Konsa
Click to expand...

This is pretty much my first serious high tech tank so I'm quite the noob 🙂
But yes I did not expect this with those salts either and I was about to give up all together.
 
Hmm tricky one, so that's three people all with the same ferts, all showing 0 with standard test kits (I assume) and a sample that got lab tested by Darrels colleague shows that it is indeed potassium phosphate.
 
AverageWhiteBloke said:
Hmm tricky one, so that's three people all with the same ferts, all showing 0 with standard test kits (I assume) and a sample that got lab tested by Darrels colleague shows that it is indeed potassium phosphate.
Click to expand...

One can assume that this might be a batch issue? It would be crazy if everyone had the same problem with these ferts. If everyone reading this with the same ferts can go to the LFS or test themselves that would be great to get a bigger picture.
I have tested my new ferts and they become dark blue as soon as I add the first drops to the solution so its not our way of testing. No offence though but you seem extremely eager to prove us all wrong.
 
Would doing a po4 test with just deionised water in then dropping a couple of grains of your po4 salt into it make a difference?
 
Hi all,
ian_m said:
Only in soft water areas is phosphate added.
Click to expand...
That would make more sense.

I know Wessex Water built both a NaOH injection plant and a phosphate dosing plant locally despite our water coming from a deep limestone aquifer (about 18dKH), but I don't know whether they use it, or exactly why they built it.

There might be some softer water from a greensand aquifer to the east of us, but otherwise it is all chalk and limestone.
AverageWhiteBloke said:
Would doing a po4 test with just deionised water in then dropping a couple of grains of your po4 salt into it make a difference?
Click to expand...
Should do.

cheers Darrel
 
AverageWhiteBloke said:
Would doing a po4 test with just deionised water in then dropping a couple of grains of your po4 salt into it make a difference?
Click to expand...
Please read through all my replies, I have tested the ready solution so not pure PO4 and I have tested with pure Vinegar as I have stated several times. Why do I feel I have to defend and repeat myself all the time.
 
Last edited:
You must log in or register to reply here.
Back
Top