Rotala macrandra

[Spnl]

I am about to siphon out the remains of my R macrandra, 3rd failed attempt with this plant. My water is London tap (I used to use RO but since upping water changes I have abandoned it, so KH 12-13, pH about 7.5 down to about 6.7 during the day, pressurised CO2 and drop checker yellowish. Dosing PMDD.
Currently using 2 T5HO FOR 9 hrs with 4 tubes on for 3hrs in the middle, Rio300 so about 300+ litres after hard scape etc.
Is my water just too hard for this plant? Or do I need to increase the light?
Any advice great fully received.

 

[Nathaniel Whiteside]

I am about to siphon out the remains of my R macrandra, 3rd failed attempt with this plant. My water is London tap (I used to use RO but since upping water changes I have abandoned it, so KH 12-13, pH about 7.5 down to about 6.7 during the day, pressurised CO2 and drop checker yellowish. Dosing PMDD.
Currently using 2 T5HO FOR 9 hrs with 4 tubes on for 3hrs in the middle, Rio300 so about 300+ litres after hard scape etc.
Is my water just too hard for this plant? Or do I need to increase the light?
Any advice great fully received.

You probably are zapping it with too much light. You should wind the lighting back to maybe 1 tube for 4-5 hours max when first planted.
I have no experience. With the plant in question, but rather, this advice is more across the board, to maximise your chances of success.

If fauna are in tank, make sure you wind the co2 back accordingly, when changing light intensity/schedules.

Remember in higher light situations, your chances of failure are much higher than at lower levels.

 

[pepedopolous]

I've had success with this plant with CO2 and low light, it recovered from an almost dead pot of the Tropica 1-2-Grow! variety.

I use tap water but the KH and GH are quite low where I am. However, I agree with Nathaniel that you should look at reducing the lighting by a lot.

P

 

[NatureBoy]

I've got this water:
Your water is classed as Moderately Hard which has a Total Hardness level of 270 mg/l as Calcium Carbonate (CaCO3).
270 Parts Per Million / 19 Clarke Degrees / 27 French Degrees / 15 German Degrees

That's a mix of ludwigia arcuata, rotala rotundifolia and rotala macranda narrow. It's CO2 injected with a similar profile to yours...lights are on for at least ten hours, two 39wt t5s. Pretty light fertilising, heavy clay soil substrate collected from great outdoors (free!), so not sure other than don't give up. Darren at Living Waters in Croydon has also had success with it in tap....

 

[Spnl]

Thanks for your advice everyone.
The suppliers generally say you need high light and soft water, so I was blaming the water. I had waited until I had cranked up the light and CO2 before planting it, but after your advice I will have another go, with lower light until it has rooted.