I had recently ventured in to the world of planted aquariums using the Dennerle system. Basically the system comprised of a heater cable laid on the floor of the tank and covered with a mixture of silica sand and compost which had been mixed half and half by volume, this layer was about 2.5cm deep. Then there was a layer of fine (1 – 2mm) quartz gravel covering the first layer and with a depth of 5cm at the front rising to 10cm at the rear. For lighting I used four x 40W trocal tubes with reflectors. I used a compressed gas CO2 system and filtration was done using an external power filter but rather than use a spray bar for the returning filtered water I extended a pipe to the floor of the tank and placed a diffuser over the end in order to minimise turbulence which could have lost valuable CO2 to the atmosphere. The CO2 unit used a solenoid which was connected to the lighting timer so that there were no CO2 added once the lights went off since plants only use CO2 for photosynthesis.
Running the tank
There was nothing out of the ordinary done regarding tank maintenance, I made a twice weekly water change and added the recommended fertilizers, iron and trace elements as directed by Dennerle for this system. The CO2 was dosed using this formula: (Tank volume in litres x The waters KH value) divided by 40 = CO2 bubbles per minute, In terms of numbers this meant (225 x 4) / 40 = 22 bubbles of CO2 per minute. This simple formula worked perfectly for me and I never had to adjust anything.
I started out using some of the faster growing plants in order to take up any excess fertilizer and CO2 so that I would avoid any early algae problems before a balance could be achieved. To my surprise all the newly added plants did amazingly well, I say to my surprise because up until this point I had absolutely no luck at growing aquatic plants. I had even switched over to all plastic plants and believe it or not even some of those were the worse for wear after years of being removed and cleaned. A friend’s comment about even my plastic plants losing their leaves meant I had to take some action and that was the inspiration behind this tank. After this early success I began searching out the plants which were supposed to be more demanding and each time they grew like weeds, so with my confidence very high I decided to go for the real difficult plants and I purchased a small bunch of Rotala macrandra and yet again it grew like a weed.
Then one day while visiting a plant specialist aquatic shop I saw a few lace leaf plant bulbs loose in a tank and on inspection they were nice and plump and very firm with a few new leaf shoots beginning to appear. So how could I resist what I saw as the ultimate challenge?
Madagascar’s Lace Leaf Plant
The bulb which I chose already had three small leaves and when I got it back home I planted it immediately. I placed it at one end of the tank just in front of some fast growing Ludwigia sp. which purely by accident provided some shade. I read all the information I could find about the plant and from what I read my tank sounded far from ideal. Most articles on line said that the plant demanded cool water 18 – 22°C and moderate shade, my set up was 26°C and very bright so I was prepared for my first failure with the Dennerle system.
Despite my pessimism the plant soon settled in and sent up several new leaves, the new leaves were straw coloured and didn’t look particularly healthy but as the leaves aged a little they slowly turned green and after just one or two months the plant seemed to be doing very well.
At this stage I made my first mistake with the plant. The Ludwigia sp. behind the lace leaf plant was very fast growing and it had created some very heavy shade, a little too much in my view, so I pruned it quite heavily in order to let some more light through and improve my Lace leaf plants chances. This turned out to be disastrous because within a couple of days leaves started to die and fall off. Realising my error I used an A4 sheet of card placed on the tanks condensation trays directly above the lace leaf plant and this had the desired effect and just as quickly as it had declined it began to recover so a more permanent method of shading the plant was made (the condensation tray over the plant was taped in to a black bin liner) and the plant continued to grow at a very good rate.
Summer came and went and in that time the temp had spiked in to the low 30’s C due to the very hot summer weather but this didn’t seem to have any adverse effect on the plant at all. So I had learned that the temperature didn’t seem to be too vital but shade was very important for the plants well being. Like all Aponogeton spp. Lace leaf plants are meant to under go a dormant period but after 18 months of solid growing mine had not shown any sign of going dormant and continued to grow at a pace.
Eventually the lace leaf plant had a height of almost 6ocm (if the leaves were held straight up) and an even bigger spread, quite simply it had out grown my tank and it no longer looked right. So the decision was made to replace it with something else since I felt I had learned all I could about the plant and succeeded completely with it, but as I later found out the plants success was even greater than I had realised.
Having grown quite attached to the plant I didn’t want to simply throw it away or give it to my Red Hook Metynnis to devour as I did with the majority of plant prunings so I took them to my local aquatic store and exchanged them for some dry goods, you’ll notice I said “them”, well yes. When I came to dig up the plant I discovered three nice healthy off shoots which had established and grown tangled with the mother plant giving the impression that there was just a single plant when in fact there were four in total.
The Dennerle system is out of favour at the moment especially the use of a heater cable. I would say keep an open mind, I went from a complete plant novice unable to grow any aquatic plant for more than a few weeks to someone who could grow almost any aquatic plant long term. As much as I would like to take the credit for this it was in fact all down to the very good Dennerle system. If I were to set up another planted aquarium in the future I really can’t see how I could get better results using a different system and so I would stick with Dennerle.