Hi
@David Edwards
It depends what you want from this plant and be careful what you wish for. Once it’s happy it will take over a tank if not constantly pruned back. There are caveats to pruning that in my experience implicate how you should ideally dose, more on that in a bit....
If you’re using RO and EI dosing there’s no reason not to give this a try. Example of how I’ve prepared water previously prior to dosing any EI at water change:
80L Total
Target ratio range:
Ca:Mg - 4:1 – 3:1 and K:Mg - 3:1 – 2:1
Ca from tap water report here puts it at an average of 116mg/l here, adjust for your area if cutting RO with tap
60 RO/20 TAP
So at water change adding in -
MgSo4
K2SO4 or KCl
I just use Epsom salt and Easylife Kalium (just potassium sulphate or chloride)
You can use salt if you got it but if not Epsom salts and Easylife Kalium are likely to be readily available as this lockdown continues from various vendors.
In real money this works out at water change as:
60l of RO
20l of tap water
8mg of Epsom salt
50ml of Easylife Kalium
So even before target EI dosing parameters for rest of the week e.g. NO3 20ppm, K 30ppm, PO4 3ppm, Mg 10ppm per week, you’ve already got the target ratios of Ca:Mg - 4:1 – 3:1 and K:Mg - 3:1 – 2:1 at water change.
Pruning:
Bit of a longer answer but may be of interest to someone else on here...
How I go about cutting Pinnatifida is also related to how the tank is being dosed at the time i.e. lean dosed (minus additional nitrate, phosphate and iron) or EI.
If we’re restricting the water column I’ll just prune leaves. Encourages smaller growth due to nutrient restriction and the high light will force the leaves to tan.
When dosing full EI the focus is on cutting the runners under the nodes to encourage spreading. Green leaves, more chlorophyll, more photosynthesis, more ability to recover = better spreading growth.
The issue with dosing the water column this way just to suit one species is it may be at the detriment to everything else in the tank. Root tabs and rich soil offers flexibility. But Pinnatifida seems to operate like a conveyor belt, cutting beneath the nodes forces new growth forwards with the top section and the old section below the cut will either snuff it or become a new conveyor belt of growth if dosing is to its liking.
A lot on UKAPS about this plant being difficult/not successful in hard water/prone to burning out.... Have grown it in extremely hard water and soft water with the same success simply by dosing according to its needs that are triggered by the aquascaper through the way its cut - simple.
Context of that conversation here:
https://www.ukaps.org/forum/threads/taking-a-sump-back-in-five-minutes.59010/page-9
Currently switching the above tank back to full tap (very hard water here) and will explain how to optimise for harder water on the above journal soon. Have run the setup both on full tap and RO/tap mix over the last eight months just to trial Pinnatifida growth under different conditions. Pruning style and nutrition both interplay in your outcome.