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

ManDrawer

ManDrawer

Member
Joined
14 Apr 2016
Messages
27
Location
Ireland
TLDR version
After a year of struggling with Plant Deficiencies while using IE starter kit , I tested my Macros with 5 tsp of Potassium Phosphate PO4 and found out there are no traces of PO4 in it..
Tested with JBL PO4 sensitive test kit, it works fine when I add Easy-Life Fosfo and it gives exact readings. After testing 1tsp PO4 salts with 20ml white vinegar it still gives no readings of PO4.

-------------------------------------

Hi,

I want to share my story with you and wonder what might be happening in my case.

Last year I purchased a starter EI kit with the following salts,
Potassium Nitrate KNO3
Potassium Phosphate KH2PO4
Magnesium Sulphate MgSO4
Chelated Trace Elements

I have been struggling for over a year with EI and Plant Deficiencies, curling leaves, GSA, GDA, yellow pin holes in leaves, you name it I have had most of it.
I thought why is this so hard while other people have so much success, and I must be doing something wrong.

At one point I went for advise to my local fish shop for advise and was told to bring a sample of my Aquarium water.
After testing 0 trace of PO4 and very high KNO3. I thought that this was strange as was dosing Macros and Micros as advised and it should contain PO4.
I didn't think much of it and thought my plants must be hungry for PO4 so I bought an extra 250ml Easy-Life Fosfo.

I never looked too much in to it anymore and gave up on my big aquarium and started over with a smaller one with all the bells and whistles, Kessil light, ADA Aquasoil Amazonia, proper CO2 setup.
Plants are doing better but still not great, I still have issues with DSA and GDA, and I try to keep my PO4 and KNO3 on a 10:1 ratio I find having to add at least 10ml Fosfo to get to around 1ppm PO4.
This is strange as I keep adding Macro's as well.

My Macro soulution currently contains,
- 500ml water
- 5tsp Potassium Phosphate PO4
- 6tsp Magnesium Sulphate MgSO4
So very strange that I have to add almost 100% of Liquid PO4 every week.

Today I got a bright idea.... (why didn't I think of this before..) lets test my Macro for PO4 with my JBL PO4 test kit, surprise surprise 0 traces of PO4..
The test kit works very accurate as it shows a perfect amount as in the description when I add Fosfo in my aquarium water.

So I either have a mislabelled PO4 pack or my salts are broken and I'm wondering if any salts including the micros are actually providing any nutrients.
Has anyone experienced something similar, or am I missing something? I also lowered my light significantly as I can't keep up with nutrients.
As soon as I get a reply and new salts I will test them straight away, not sure yet how to test trace element's though.

I emailed the shop I purchased the pack from, still awaiting an answer.
I obviously won't name them.

Aquarium specs:
Eheim Aquastar 54 Litre 60cm x 30cm x 30cm (w x h x d)
Filter, Fluval 406 Canister
CO2 system, Pro Aquarium CO2 System With Adjustable Pressure For Aquarium 50L - 500L
Light, Kessil A160WE Tuna Sun: max 40% max Intensity 20% Colour 10 hour period. (HC Cuba)

M1asAgG.jpg
 
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Hi all,
ManDrawer said:
lets test my Macro for PO4 with my JBL PO4 test kit, surprise surprise 0 traces of PO4..
The test kit works very accurate as it shows a perfect amount as in the description when I add Fosfo in my aquarium water.
Click to expand...
If you have <"hard water"> the PO4--- ions will rapidly go out of solution as insoluble phosphate compounds (<"most phosphate compounds are insoluble">). If you acidify your macro-solution (you can use "white vinegar" or ascorbic (or citric) acid), and re-test your macro-solution should find some PO4.

If you don't then it is likely that your salt (KH2PO4) was mis-labelled when you bought it.

Potassium di-hydrogen phosphate (KH2PO4) is naturally an acid (you have one K+, but two H+ ions in solution), so you could make a separate stock solution of it, even though you may still have problems with the formation of insoluble calcium phosphate complexes etc. in the tank.
ManDrawer said:
Easy-Life Fosfo
Click to expand...
It doesn't make any difference where an ion came from, every PO4--- ion is the same as every other PO4--- ion, they have been on earth for the last several billion years, <"continually being re-cycled">.
ManDrawer said:
I also lowered my light significantly as I can't keep up with nutrients.
As soon as I get a reply and new salts I will test them straight away, not sure yet how to test trace element's though
Click to expand...
It is not easy to test for the full range of micro-nutrients, even with analytical grade equipment.

cheers Darrel
 
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Hi Darrel,

Many thanks for your reply, the Fosfo and Macro solution are both tested with the same test and same water, Fosfo clearly shows a blue solution the Macro doesn't change colour one bit.
I think the salts are mislabelled, I might order a new one from another source to test. (Unless they are going to send me a new package which I doubt)
I will buy all new as I now don't trust any of their salts anymore unfortunately.

However I will try what you say with pure PO4 salts and Vinegar.
 
Weird.... even with a commercial PO4 fertiliser you still show nothing? There must be something wrong with the test kit.

I use API phosphate test kit, but only to see if I have any present. I don't pay attention to the colour match..... just the fact that if there is colour, there's at least some phosphates.
 
I'm using JBL Test PO4 sensitive, and it is working fine. If you read the full story you see when I use Easy-Life Fosfo in my tank it gives the exact reading. JBL Test PO4 sensitive gets more blue the more PO4 it detects. I updated the TLDR to avoid confusion.

I just ordered 100G of All-in-One Complete Macros And Micros Fertiliser lets see how that goes.
 
Small update, have been using new ferts no more algae and my plants look amazing.

I did trim out the leaves with algae on it a while ago, I also turned the rocks around and for 2 weeks no no algae what so ever.

IMG_20170912_154136.jpg
 
And a week later, plants are doing amazing. No more Algae, light Kessil A160WE Tune Sun is on for 9 hours of which 3 hours on 95% no algae or anything.
I'm now using this CO2 supermarkets 'All-in-one' Macro & Micro fertiliser and its doing great, really recommend it.

IMG_20170920_160157.jpg
 
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What's it look like when you compare it to other salts? I find po4 looks like crystal snowflakes (best I can describe :D) when dropped in the water. Magnesium looks like sugar, potassium sulphate is fine like salt and kno3 slightly larger and clumps together in the container. Maybe you could identify it and use it anyway if it was mislabelled any way. If you bought some deion water and you have test kits you maybe could ascertain both visually and using tests what you actually have. Waste not want not is my motto.
 
AverageWhiteBloke said:
What's it look like when you compare it to other salts? I find po4 looks like crystal snowflakes (best I can describe :D) when dropped in the water. Magnesium looks like sugar, potassium sulphate is fine like salt and kno3 slightly larger and clumps together in the container. Maybe you could identify it and use it anyway if it was mislabelled any way. If you bought some deion water and you have test kits you maybe could ascertain both visually and using tests what you actually have. Waste not want not is my motto.
Click to expand...

Hi, I did compare with pictures actually in a chat in the background, looks normal. I'm also waiting for people with the same PO4 salts to come back with test results. Either way I moved on with these new ferts and they are great, loads of PO4 in them when I tested. It's also not EI, with every other day and 50% water changes (Which is brutal on my shrimp with my small tank) simply daily dosing no hassle, I can get my kid or wife to do this as well.

I also contacted the shop and it could not possible a mixup as their quality control is top notch, so in other words its probably my fault and something I did with the salt (as always)

Here is a picture of the salt.
IMG_20170828_193622.jpg
 
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Yeah, it looks the part I have to admit. Sort of top layer fresh snow.
 
dw1305 said:
Hi all,@Zeus., sent me a salt to test, and Ceri, our analytical chemist, can confirm that it is potassium dihydrogen phosphate (KH2PO4).

cheers Darrel
Click to expand...
Hi Darrel, Thanks for that I did however not mention the shop name here :)
I knew that would be the case, I'm just unlucky or my PO4 has magically dissolved in to thin air.

If you want I can send you my bag and you can do with it whatever you want.

Anyway no worries though I moved to a new product and its working great.
 
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ManDrawer said:
Hi Darrel, Thanks for that I did however not mention any shop names here :)
I knew that would be the case, I'm just unlucky or my PO4 has magically dissolved in to thin air.

If you want I can send you my bag and you can do with it whatever you want.

Anyway no worries though I moved to a new product and its working great.
Click to expand...
I think inadvertently you might have named a brand if I'm reading this right but it's OK it's been cleared up now. If you're not sure what I mean pm me and maybe you can ask a mod to change it as your ability to edit that post might be gone now.

Sent from my STH100-2 using Tapatalk
 
AverageWhiteBloke said:
I think inadvertently you might have named a brand if I'm reading this right but it's OK it's been cleared up now. If you're not sure what I mean pm me and maybe you can ask a mod to change it as your ability to edit that post might be gone now.

Sent from my STH100-2 using Tapatalk
Click to expand...
Sorry I edited the post I mean the shop I purchased the PO4 salts from (Naming and shaming). The other shop names are only positive so there shouldn't be a problem there.

They company I purchased the PO4 salts from offered me a refund or new salts but as I owned the salts for almost a year I don't think that would be fair, and I was more interested in stepping away from EI with an All in one product.
The only thing that gave me a bit of a bad taste in my mouth, was the fact that the shop stated that it could not possible be something bad done on their part. And when I offered to return the bag for further investigation they did not show any interest what so ever.

Only thing I want to get across with this thread is that it's probably more advisable to test your salts and not blindly trust the labels.
 
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I have been having the same issues here as ManDrawer.

If you check on my post history I came on here for some advice about it.

Anyways I have also ordered a different fert. Also going for an all in one option I'm going to try "the aquascaper complete plant food".

Adding K2SO4 to my macro solution did fix the problem of holes in leaves. I bought this separately from ei starter pack.

my tank is low tech
 
Are people testing for po4 using the salt in pure water or in tank water, 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?
 
I haven't tested for phosphate yet as I don't have a test kit, hopefully will get one today. I have however ordered a different plant food. I'll let everybody know my results.

New plant food should be arriving tomorrow from aquarium gardens.
 
OK results of testing.

Macro fertiliser with 1 teaspoon of KH2PO4 - no phosphate present @ 0 PPM.

I never do water testing so I decided to check the tank water 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.
 
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