# Phosphates 2.5+ in my tap water.



## Mark.A (21 Apr 2020)

Hey all, I am currently cycling my tank and whilst I was testing the tank water for ammonia I figured I'd test my tap water for Nitrate and Phosphate. Nitrate is almost zero (maybe 1) but Phosphate is 2.5 possibly slightly more.

I was planning to dose TNC Complete once the tank is setup but now I'm thinking that's going to be no good because of the already existing Phosphates in the tap water. Can someone confirm this is the case?

I will be doing 50% weekly water changes to reset everything but as the tap water has Phosphates in already it will be resetting the Phosphate levels back towards 2.5-ish once I do the weekly water change.

If the TNC complete is no good I presume I will be best making up my own EI mix? Any advice on what I would need to mix taking into consideration the existing Phosphate?


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## Zeus. (21 Apr 2020)

I personally wouldn't trust a test kit *What about Test Kits ?*
Getting you hand on your water report form your water supplier is the best bet, then see what the seasonal range is for PO4 and use the lowest value.
Then use that value to calculate how much PO4 your adding with your weekly water change.

Just so happens that my new fert calculator does all the maths for you

eg




Not only does it do that it does all the maths for you to 'clone' some commercial ferts (the pics below did not have any PO4 in the tap water added )





then gives you the salts to add to your dosing bottles for your tank, if the salt isnt need to reach the weekly ppm target than it doesn't use it





and a complete report on whats been added from salts and WC over the week, plus allows you compare other fert regimes





So making your own DIY ferts has never been easier IMO

Zeus


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## Mark.A (21 Apr 2020)

I already checked the water quality report. I have one from 01/01/2018 to 31/12/2018 but it doesn't have PO4 on it at all.

I've attached the report.


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## Zeus. (21 Apr 2020)

Mark.A said:


> I already checked the water quality report. I have one from 01/01/2018 to 31/12/2018 but it doesn't have PO4 on it at all.



Same here so trust your water report and not your test kit, ferts in excess isnt a problem as long as you do a WC to suit your fert regime


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## Mark.A (21 Apr 2020)

Zeus. said:


> Same here so trust your water report and not your test kit, ferts in excess isnt a problem as long as you do a WC to suit your fert regime


No, I don't mean the water quality report says there is no PO4. I mean that the level of PO4 is not in the report at all.

So what you're saying is it doesn't matter if there is too much PO4? ...and I can just dose the TNC Complete and not worry about the extra PO4?


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## Zeus. (21 Apr 2020)

Well heres a comparison of EI fert dosing and TNC





So even if your test result is correct 2.5 + 0.62 = 3.1ppm PO4 thats only 0.1ppm above the EI upper range for PO4



Mark.A said:


> So what you're saying is it doesn't matter if there is too much PO4?



In your case yes, there are upper limits OFC, but cant see you hitting them


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## Sammy Islam (21 Apr 2020)

Mark.A said:


> No, I don't mean the water quality report says there is no PO4. I mean that the level of PO4 is not in the report at all.
> 
> So what you're saying is it doesn't matter if there is too much PO4? ...and I can just dose the TNC Complete and not worry about the extra PO4?



No need to worry about the po4. If you plan on dosing EI levels with TNC complete, the po4 in your tap water will actually help because TNC complete is low in po4 when dosing to EI levels.


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## dw1305 (21 Apr 2020)

Hi all,


Mark.A said:


> but it doesn't have PO4 on it at all.


There isn't a statuatory requirement to report it. There isn't a maximum permitted value for phosphorus (P), or orthophosphate (PO4).

It is the same with magnesium (Mg). We are interested in its level, but there aren't any statutory limits, so most water companies don't report its level in your tap water.

Because of the low NO3 value it is unlikely there is much PO4--- in your source water, but your water company will have added somewhere in the region of 0.5ppm PO4---, along with sodium hydroxide (NaOH), to control the levels of lead (Pb), zinc (Zn) and copper (Cu) the technical term is phosphate induced metal stabilisation (PIMS) for the <"control of "plumbosolvency">.

Have a look at <"Public water supplies in the Northern region of England July 2016">.

cheers Darrel


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## kilnakorr (21 Apr 2020)

Zeus. said:


> Well heres a comparison of EI fert dosing and TNC



Maybe fix the typo in the spreadsheet? Says 'tMc' in the picture.
Better not confuse people about ferts, it's confusing enough already!


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## Zeus. (21 Apr 2020)

kilnakorr said:


> Maybe fix the typo in the spreadsheet? Says 'tMc' in the picture.
> Better not confuse people about ferts, it's confusing enough already!


l

Cheers m8 

One of the joys of being dyslexic - your mind auto corrects everything into what it thinks it should be, so spotting typos is hard


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