Starting Utricularia graminifolia with DSM

[wolfiewill]

I'm been attempting to grow Utricularia graminifolia as a carpet plant in an 15 gallon iwagumi set up. This led me to do an online search to see what conditions have worked for others. In addition to the usual specialty web sites I looked at various blogs as well. So what follows is the progress I've made to date, and what I'm going to do in the next few weeks based on the research. I'd really like those of you who have grown UG to weigh in on this topic.

I found good information from a member on UKAPS who suggested that a dry start method would be the easiest and had worked very well for him on a number of occassions, so I started it that way. The substrate is Fluval Stratum (1-1.5 inches) on top of a layer of Seachem Flourite (1-1.5 inches). Next the tank was filled with tap water and dosed NO3 (10ppm), PO4 (1ppm) and Seachem Comprehensive (to 0.1ppm iron) and left the tank to soak for a few days. The tank was then emptied to the point where the water level was just at the top of the Stratum layer, and then I merely sprinkled the UG on top - no planting - and waited. It has been 2.5 months to date, and here is a photo to show what it looks like.

Next I did an online search, and here is a meta analysis.... of sorts, of what I found. Sources include Aquascaping World, bubblesaquarium.com, carnivorousplantnursey.com, UKAPS, aquazone.io, flowgrow.de, and heaquariumguide.com. I separated the information into the following categories: Lighting, CO2/pH, fertilization, substrate type, water parameters, and maintenance. And here is the summary of what has proven successful for others.

Lighting: There was very little agreement among the sources. However, several sites suggested that starting with low light and increasing the intensity after 4 to 6 weeks to high light.

Carbon source: CO2 injection was universally suggested once the plant was submerged. Target pH ranges suggested went from 5.0-7.0, but an acid environment was universally recommended as well.

Fertilization: There was very little agreement concerning macro fertilization. Water column dosing worked for some but several suggested that rain water worked as well. Micro nutrients, particularly iron and manganese were mentioned as important by several sites.

Substrate: Substrates that worked went from none (on a log), to nutrient rich.

Water parameters: There was no agreement as to water hardness. Temperature ranges were from 64-77̊F.

Maintenance: Regular trimming was almost universally recommended. It seems that melting at the substrate surface was the most common problem and trimming to 1 cm seemed to control this problem. One interesting comment on the aquazone.io website was that melting occurs due to ammonia build up in the substrate/root zone. In a natural environment the ebb and flow of river/stream level removes this but in the aquarium regular trimming was necessary. Alternatively, a daily ebb and flow strategy, one to several times per day would imitate the natural processes and maintain the mat density.

So, here's what I'm going to try. I'm a couple of weeks away from filing the tank as the plant has carpeted much of the substrate. First I'll test the light so I can duplicate the intensity after filling the tank. Then I'll fill the tank with regular city of Ottawa tap water, and adjust the light intensity to compensate for the addition of water. I'll add good filtration and flow using an Eheim 2213; add CO2 to drop the pH one pH unit from the baseline each day; fertilize the water column to 10 ppm nitrate, 1 ppm phosphate and add Seachem Comprehensive to target iron at 0.1 ppm. I'll gradually increase the light level if there are any indications that it's not intense enough, and of course trim to 1 cm regularly. Comments?

Summary of Online Search:             
Lighting:                 start low; go high after time;                                           
CO2   :                 CO2 recommended; (I'm going to start @ 1 pH unit drop/day);
Fertilization:          varies from nutrient poor to nutrient rich; micros constant;
Substrate:              varies from no soil to nutritious substrate;
Maintenance:         regular trimming necessary;