What Makes Ludwigia Red?

[rms]

My understanding was it's down to how much light you have, as long as sufficient nutrients are provided, which they are.
 
I have 49 watts for 6 hours and 98 watts for 3 hours in a 125l (33g) tank. My ludwigia grows quickly and looks very healthy, but it's green.
 
Any help appreciated

 

[attibones]

I think iron turns it red, but could be wrong.

 

[rms]

I'm dosing macro/micro ie method, plus root ferts, which include iron (mostly for the swords benefit), and I put a small amount of EasyLife Ferro (iron fertiliser) once a week.

 

[techen]

A lot of Ligggghhhhttt, Without the light they'll turn green.
 
And when I say a lot of light, you'll want a good 3.5 - 4wpg with gas CO2 injection.

 

[rms]

I have 3w per gallon, my drop checker shows pale lime green, so on the cusp of enough and too much - I have studied my fish very carefully and they are fine. My swords and sao paulo are beeding, the ludwigia a little beeding, so they seem happy enough. All are growing very well and the swords are looking very healthy. My sao paulo is trying to turn magenta - the tips are there and fading to green over a few centimeters. Please don't say 3w isn't enough. I only just bought this light unit and the missus will kill me if I even suggest an upgrade..... 

 
The light unit runs T5HO's so I'm kind of maxed out there...

 

[DrRob]

3W should be plenty. I've seen red plants grow happily in far less. I've also seen all sorts of debate about micronutrient issues, lighting spectrum issues and such like, but the main problem has generally been CO2 issues.
 
Iron can be an issue if it's dropping out of suspension.

 

[rms]

3W should be plenty. I've seen red plants grow happily in far less. I've also seen all sorts of debate about micronutrient issues, lighting spectrum issues and such like, but the main problem has generally been CO2 issues.
 
Iron can be an issue if it's dropping out of suspension.

 
I don't think I need more co2, my drop checker is pale lime green. What means 'dropping out of suspension'?

 

[rms]

It's occured to me it might be my tubes. I have 4x 6,500k. Would changing a couple help? If so cooler or warmer?

 

[Tongue_Flicker]

Good bright lights of course, acidic substrate medium (i guess in this case) as well as iron content of soil. Using laterite would definitely help here to avoid overdosing the plant with too much iron

Notice how hydrangeas flower pink in acidic soil and horsetail grass turns bronze brown in acidic waterlogged soil

 

[rms]

Laterite?? I thought Fluval Stratum would suffice with root ferts 

 Do you really think it might help? 

 

[DrRob]

 What means 'dropping out of suspension'?
 

 
Precipitating, chelating or being otherwise bound in such a way that the iron is no longer usable by the plants. There are a huge variety of things that do this, and it's the reason that we don't mix micro and macro without adding in agents to stop things reacting.

 

[rms]

 

 What means 'dropping out of suspension'?
 

 
Precipitating, chelating or being otherwise bound in such a way that the iron is no longer usable by the plants. There are a huge variety of things that do this, and it's the reason that we don't mix micro and macro without adding in agents to stop things reacting.
 

 
I've tried to find out about this, but seem to be coming up blank. When you say 'agents' what are you adding exactly?

 

[DrRob]

OK, now the botanists may shoot me down on some inaccuracies, as may the chemists, but from my understanding;
 
Iron is available to plants mainly in it's chelated form. Most iron salts such as the common oxides aren't available in the water column and require some chemical conversion by the plants to make them absorbable. Plants possess the systems to do this and will internally stabilise iron fairly easily.
 
In an ideal world an acidic environment will encourage the iron into suspension, however most of our tanks are on the more alkaline side, and fertiliser mixes tend to be far closer to pH's of 8, and it's fairly easy to end up with insoluble iron salts if the macros get their hands on the iron. This is often avoided by changing the pH of the mixed fertilisers, usually by adding things like ascorbic acid.
 
The problem we can get in aquariums is that many iron complexes that form are readily available to the plants, but many aren't. So in our closed systems it's possible to get the iron being pinched into complexes that can't be accessed by the plants and there are many, many variables in closed systems.
 
I can start blathering on about photostability and bioavailablity of EDTA etc, but to be honest my own recollection of the chemistry involved starts to struggle, so I'd be starting to get quite vague.

 

[rms]

OK, now the botanists may shoot me down on some inaccuracies, as may the chemists, but from my understanding;
 
Iron is available to plants mainly in it's chelated form. Most iron salts such as the common oxides aren't available in the water column and require some chemical conversion by the plants to make them absorbable. Plants possess the systems to do this and will internally stabilise iron fairly easily.
 
In an ideal world an acidic environment will encourage the iron into suspension, however most of our tanks are on the more alkaline side, and fertiliser mixes tend to be far closer to pH's of 8, and it's fairly easy to end up with insoluble iron salts if the macros get their hands on the iron. This is often avoided by changing the pH of the mixed fertilisers, usually by adding things like ascorbic acid.
 
The problem we can get in aquariums is that many iron complexes that form are readily available to the plants, but many aren't. So in our closed systems it's possible to get the iron being pinched into complexes that can't be accessed by the plants and there are many, many variables in closed systems.
 
I can start blathering on about photostability and bioavailablity of EDTA etc, but to be honest my own recollection of the chemistry involved starts to struggle, so I'd be starting to get quite vague.

 
I ordered my salts from TNC and they specifically ask if you have hard or soft water. I know this is different to pH, but both pH and KH in my tank are lower than my tap due to the CO2 injection. I ordered the salts for hard water, which is true to my tap and they (TNC) stated additional elements are added to the cocktail to ensure the plants absorb the trace elements.
 
I wasn't aware of the expression "dropping out of suspension", but this is making a lot of sense now.
 
If my tank is more acidic, but I'm adding ferts for alkaline water, will this have a negative effect on suspension? It would seem so judging by my very green, but healthy ludwigia 

 

[SO19Firearms]

The pH is an excellent call. Especially when you mix that in with the "plenty of CO2" call and it's resulting pH drop....*

The Iron call is always tricky - It's in a lot of books so I'm inclined to ignore it outright but it's dropping out is always valid with phosphates in the water - but then nobody (especially chemists

) ever wonders about the phosphorous solubilising bacteria that try so hard to reverse that.....

As an aside - you can't presume your CO2 is fine because your DC is lime green - it's definately a start and the right place to be but we don't know that something needs 40ppm or 60ppm....or wether the flow's good etc (but that's not a slight - it sounds like you're def doing things right)



*somebody set up some controlled tests and we'll know.....