Algae and CO2 question

Yep, you've now run out of NO3/PO4/K and traces even.

I'm pretty certain that this is some nutritional deficiency.

Yep.

Tank chemistry is pretty normal (detailed below), only change since I
introduced the CO2 is nitrate has dropped from 10-20 ppm to 0 ppm

Yep, there's a big problem and you'll get algae from this.

Is this a likely outcome of plants using all of the Nitrate, or is there
some other missing or excessive nutrient at play?

You've run out of NO3, maybe K+ and maybe PO4, perhaps you need more
traces.

Here's what I'd do.
Get 4 things:

KNO3
K2SO4
KH2PO4
Tropica Master grow or equilivant trace mix.

You can get these in the UK from a couple of places, do a search for
PMDD supplies in the UK on this board, the Tropical Fish Center,
AquairumCentral.com etc.

Your routine might go a little like this:
40-50% water change a week.

After water change:

Add 1/3 teaspoon KNO3 (+feed fish well during the week)
Add 1/2 teaspoon K2SO4
Add 3-4 rice grain's worth of KH2PO4.
Add 8 mls of Tropica master grow 2x a week.

You might need to add a bit more Traces and KNO3 depending if the tank
is doing good.

You have good light/CO2, all you need is the nutrients.

Regards,
Tom Barr

Chemistry

Tank: 55 gal
Light: 1.6 wpg
pH: 7.0 (controlled by pH controller)
kH: 7
gH 5
Ammonia: 0
Nitrite: 0
Nitrate: 0
PO4 Unknown.



Graham.

Hi Tom,

Sorry for not responding sooner, wife had a baby the same day I posted the
question and life has been a little hectic since then

" wrote in message
om...
Tank chemistry is pretty normal (detailed below), only change since I
introduced the CO2 is nitrate has dropped from 10-20 ppm to 0 ppm

Yep, there's a big problem and you'll get algae from this.

And did I :-)

You've run out of NO3, maybe K+ and maybe PO4, perhaps you need more
traces.

Here's what I'd do.
Get 4 things:

KNO3
K2SO4
KH2PO4
Tropica Master grow or equilivant trace mix.

You can get these in the UK from a couple of places, do a search for

I'm actually in Australia, but I managed to find Potassium Sulphate (K2SO4)
at a
garden nursery. KN03 is difficult to locate, but I'm using Seachem Nitrate.
Using Seachem Flourish for Trace elements although I'm dosing around 10 ml
twice weekly to keep the Fe at around 0.25ppm

PO4 in my tank is around 0.25 ppm which is stable.

Your routine might go a little like this:
40-50% water change a week.

After water change:

Add 1/3 teaspoon KNO3 (+feed fish well during the week)
Add 1/2 teaspoon K2SO4
Add 3-4 rice grain's worth of KH2PO4.
Add 8 mls of Tropica master grow 2x a week.

Using your formula above as a guide has worked wonders for the plant health,
although the water is not as clear as I would like. It'll probably settle
down once the tank stabilises.

Thanks for the help. Much appreciated.

You have good light/CO2, all you need is the nutrients.

Regards
Graham.