Phosphate Problems

Hi Prof!

I have a newly set up tank that is quite close to being fully cycled; im in Grahamstown.

The tank was filled with tap water (the pH after standing overnight is 7.4 (GH and KH both of 1) and the ammonia is 0.65ppm :sick

My tank has taken the ammonia down to 0.3ppm but my phosphate reading is off my test kit range > 10mg/pl

The water has a green ting to it, lol...I dare not turn any lights on.

Currently I have Seachem Phosguard ordered to to reduce the phosphate.

But why is the reading so crazy? I only just put fish in (there was no feeding or anything!)
My NO2 and NO3 readings are zero (I have an established bio filter[as shown by it filtering out all the ammonia from the stupid tap water])

My tank has lots of oxygenation but no CO2 production could this be the problem of the crazy PO4 reading??

Thanks in advance;
AJ

 

Hi AJ,

Before I try to answer, just do me one favour and that is that you measure the phosphate levels of your tapwater please.

I can then perhaps come to some sort of a logical conclusion.

Kind regards,

Dirk

 

I have the same issue with Phosphate. Have never added anything to increase the levels, yet after starting a new tank – or even in my established tank - it’s at 10mg/l.
But it doesn’t seem to have any effect on the fish so I’ve always left it.
But would also like to hear what Dirk thinks.

 

Oh Yes,

And one more issue that I would like to ask both of you to reply to is whether you are using any enriched substrates or whether you are using pure gravel.

Kind regards,

Dirk

 

I'm using plain silica gravel, so its not coming from there.

 

Hi Phinix,

Whilst we are waiting for AJ's reply, I may as well explain what is happening here. Phinix in your case, the water that you are getting must be coming from Voëlvlei Dam. Many of the areas around Table Mountain get better water from the Woodhead Reservoir on Table Mountain, and that water is completely phosphate free, but the water from Voëlvlei Dam is runoff from wheat fields which are fertilized with phosphate and for this reason the phosphate levels are as high as you are measuring. Although there are repeated debates on this forum about phosphate and whether it causes algal growth, I have no doubt that this can be the cause of algae if the phosphate level is as high as you say.

Now I would like to know from AJ if his tap water already measures high phosphate because that would be the source of the problem as the dam must then be getting water from an agricultural area, or if he has a substrate that contains supplements as this could then be the reason for the high phosphate. However, I also want to ask you to make sure that your phosphate test kit is giving an accurate reading, because this may also be misleading you.

Kind regards,

Dirk

 

i cant say if you are using a sera phosphate test kit they are HIGHLY inacurate. my tank max out the scale on that test kit and i think its 10ppm if im not mistaken. this would cause seriouse algae issues as i also have high light witch would fuel algae.

 

@Lloydster,
What would the accurate way be, to measure phosphates if the sera kits is inacurate ?

 

Hey thanks for the reply's so far

So what I have to add is; my tap water phosphate is 0.1 but this isnt tap water from the same week as the one I put into the tank...The PHD chem student in the flat above me thinks that I might have got water from a day when it wasnt treated correctly at the waterworks, and given the state of grahamstown water...I wouldnt be surprised.

As for my substrate; im using river gravel from my farm which was washed about 100 times We did test the unwashed river gravel after letting in stand in some water for 3 days and the phosphate reading was 1mg/l. Could high oxygnation increase the phosephate?

Thanks,
AJ

 

@gdt78 there you go bud..
http://www.plantedtank.net/forums/f...83545-calibrating-test-kits-non-chemists.html