Originally Posted by Cja313
Water sprite is one of the easier growing plants from what I gather when left floating. Whats the bare minimum of supplements to add to the water to have it grow. Would it get all the nutrients it needed from Fish/Food waste or would I need to dose with Plant nutrients as well?
It depends. Nutrients come from various sources naturally. All nutrients will come from fish foods, but I do not recommend overfeeding fish just to get better plant growth, and minimal fish feedings may not necessarily provide sufficient nutrients to balance the light. Other nutrients occur in the water, hence regular water changes; this primarily replenishes the hard nutrients that are macro-nutrients, namely calcium, magnesium, potassium. Water Sprite is a soft water plant naturally, so its uptake of these is likely less than some plants like swords would be, but still they are essential macro nutrients. Then there is the light; more light or longer duration (provided the intensity is sufficient to start with) means more nutrients to balance, otherwise the plants will slow photosynthesis and algae has the advantage.
Floating plants generally require more nutrients because they grow faster. This occurs because they are closer to the light so intensity is rarely a problem, plus they are able to assimilate CO2 directly from the air which gives them a faster supply and more of it.
If I do not add Flourish Comp to my tanks at least once weekly, the Water Sprite (which I have in all but one of my tanks at the moment) begins to fail. It slows in growth, and the leaves begin to break apart. I have experimented over the past year, and with two weekly doses of Flourish Comp it improved significantly. I went to three doses per week, and it improved further again. Just to complete the picture, I've gone back to twice weekly as this results in good response from all my plants.