When To Dose Po4 And No3

[Themuleous]

So I did my regular dosing of PO4 (1.5ppm) and NO3 (15ppm) this morning, but this evening I have done an 80% water change, do you think I should dose again? What do people who do twice weekly water changes do about keeping the levels up and/or when do they dose? I would have thought not dosing again would leave the PO4 and NO3 levels very low for a day, could this been a bad thing?

Thanks all

Sam

 

[George Farmer]

As long as the NO3 and PO4 are within limits i.e 5-30ppm NO3 and 0.5-3ppm PO4 or thereabouts then don't worry. Remember, it's Estimative. Also remember that your plants will have "luxury uptaked" whilst you've been dosing EI and thus a day or so with low NO3 or PO4 won't do any harm.

That's heavy dosing Sam. Are you getting uber-growth?

 

[Themuleous]

The HC has finally taken off and it growing great, its even smothering the BBA which I hope means I've finally kicked that and the staghorn in the butt, here's hoping!

I was dosing 1 PO4 and 10 NO3, but having tested I realised the PO4 was quite low at the end of the week, so increased that to 1.5ppm. Have also recently noticed the HC developing translucent leaves (the new ones rather than the old leaves), which I thought could be due to low NO3 so upped that as well, but having read a recent thread think it might be due to excel which I have also been adding to help against the BBA.

What would you recommend? Whats your cube dose rate? I have read in the past on APC that you often need to dose more PO4 relative to NO3 i.e. at a ratio of 1:3/4 rather than 1:10 to get the required level?

Either way the HC is pearling like mad and so is the riccia (which was also affected by the excel) so I know they are both doing ok. Should I drop back to 1ppm and 10ppm?

I do seem to be getting quite a bit of very fine thread algae at the moment so something still isn't quite right/balanced. But that could be because I'm down to just one shrimp as the others have been dropping like flies recently!

Thanks George

Sam

 

[JamesC]

What would you recommend? Whats your cube dose rate? I have read in the past on APC that you often need to dose more PO4 relative to NO3 i.e. at a ratio of 1:3/4 rather than 1:10 to get the required level?

I add NO3/PO4 in a ratio of 4:1 as this is the ratio that I've worked out from the EI article on Tom's website. On my 200 litre tank this works out at 8ppm NO3 and 2ppm PO4 per dose. I actually put in slightly less at 6ppm NO3 and 1.5ppm PO4 which works well for me. Any lower on the PO4 and I get green spot algae very quickly. Haven't got a clue what the NO3 and PO4 levels in the tank are as I never test. Started to do 60-70% water changes now so I know levels will never get that high.

HTH
James

 

[Themuleous]

Cheers James, might start dosing 1.5 PO4 and 10 NO3 as I know HC can be very N hungry, sound like a good idea?

Sam

 

[George Farmer]

HC will soon let you know if you need more NO3.