A reader asks for advice on which plants to use in a trickle filter. PFK expert Jeremy Gay gives advice.
Q: I am wondering if I can put house plants in the trickle filter of an AquaStyle 980 aquarium. If so, what would be the best media to use, and would you plant all of them or just some? Which plants would you recommend? I also have an Aqua 750 external filter running with this tank.
ALISON KING, VIA EMAIL
A: Jeremy replies: I would either use hydroleca (available from garden centres and reptile shops,) or rock wool of the type used for potted aquatic plants.
Hydroleca is a baked clay ball that doubles up as a biological media (good for nitrification) and the rock wool is used commercially in hydroponics as a rooting medium for everything from aquatic plants to lettuces. The beauty with both is that they are inert so you feed the plants with a good, complete liquid fertiliser just like you would with plants under the water in the tank below.
For the best growth and nutrient export (by which we mean the lowering of nitrate and phosphate levels), use a clip-on grow light with either red or magenta LEDs above the tops of the houseplants.
There are many species of houseplant you could use to plant your trickle filter, from Dracaena to ferns and Fittonia to Pothos.