What ferts should I be using?

[Tim]

I have a 75 gallon with 240 watts of lighting.
I have DIY co2 and am adding flourish.
Anything alse I should be adding? I am finding the leaves on my swords are "rotting" after a while.

Thanks

[BigDaddy]

Tim...

With your lighting over that size tank, you need to dose NPK and traces individually.

Here's my routine (same size tank, 220W lighting and pressurized CO2)

3 x a week... 1/2 tsp of KNO3 dosed dry
2 x a week ... solution of KH2PO4 to increase P to .35ppm total
3 x a week... 15mL of trace mix (flourish will do, but is expensive.  Get a trace element mix from a hyroponics place instead 2 tbsp to 500ml of distilled water).

Your swords will also do very well if you put root tabs underneath them.

[redbelly]

where do you get the KNO3 and KH2PO4 from?
do they also come from the hydroponic stores?

[Tim]

Tim...

With your lighting over that size tank, you need to dose NPK and traces individually.

Here's my routine (same size tank, 220W lighting and pressurized CO2)

3 x a week... 1/2 tsp of KNO3 dosed dry
2 x a week ... solution of KH2PO4 to increase P to .35ppm total
3 x a week... 15mL of trace mix (flourish will do, but is expensive.  Get a trace element mix from a hyroponics place instead 2 tbsp to 500ml of distilled water).

Your swords will also do very well if you put root tabs underneath them.

Is there test kits I can get? If so can I get them at big als? Also where is the best place to by KNO3 and KH2PO4?

[BigDaddy]

I use the Seachem nitrate and phosphate test kits. They are more expensive, but more accurate, especially in the low ranges.  Iron kits have proven to be inconsistent for most planted tank keepers (variation in organic matter makes them less reliable or so they say)

Potassium Nitrate and Mono Potassium Phosphate can be purchased at Upper Valley Hydroponics, or any other hydroponics shop. Same thing with a trace element mix.