When to use NPK?

[Cowboy]

When would be a good time to start using macro nutrients? I currently have about 3watts per gallon of t-5 lighting. I use flourish excel, ferro-vit, micro nutrients and potassium. In the past, I have relied on the fish to provide the N and P.

Any advice would be appreciated.

 

[ed seeley]

Well by UK standards you're fairly high light there so I'd advise using macro fertilisation straighht away! As you're using Excel rather than gaseous CO2 I'd probably try half dosing. What method are you using to work out your dosing levels? EI? If so don't forget the large water changes - I find the Apistos really like them too.

 

[Cowboy]

Thanks for the reply. I am using gaseous CO2 as well, but the extra boost is comming from the Excel. For dosing, I must admit that I am dosing in relation to the bottle recomendations. Is that not a good way to do it. I looked up the EI instructions and might do that. I change roughly 30% of my my water per week. The plants seem to be growing well. The only thing that I have noticed is my Rotala wallichii is not as red as I would like it. Also, my Echinodorus 'Red Diamond' is more pink than red.

 

[ed seeley]

IMHO EI is a nice method to use for two reasons. It provides a slight excess of nutrients (so the plants never run out of them and stop growing) and it's easy to with dry powders (so it's much cheaper buying bottles of commercial ferts). However if you don't want to go with powders then I'd certainly recommend trying Tropica Plant Nutrition Plus as an all-in-one fertiliser with micro and macro nutrients.

To be honest under that lighting you'll probably need much more nutrients than the standard dose, but you want to be doing all of them in enough quantities or algae (that can do better under conditions with nutrient imbalances) can get going.

Pale colours can be a sign of as lack of micronutrients (especially Iron) but could that's not my area of expertise (especially as I'm colour-blind!). I'd just start by trying a more complete dosing regime and see if that cures it first.