Doulbe watts. How to make the transition.

[Sarpijk]

Ok. So I have decided to double my lighting from 24 to 48 T5 watts. This is for a 60 litre tank and I have decided to do so because I have trouble growing some of the most demanding plant species.
How should I make the transition? Should I start increasing the lighting hours progressively or can I get away with no changes at all?

 

[Crossocheilus]

If you can I would raise the lights up high, possibly using one of the par/distance graphs to estimate at what height the doubled wattage will output the same par as before. Then you can slowly lower the light unit, increasing CO2 as you go until you reach an optimum level.

If you can't do this gradual change you would have to increase your CO2, look for a green/yellow dc and 1 point pH drop by lights on time. Even then you may struggle with the transition as your entire system will be adapted to lower light. Perhaps perform extra water changes if you see plant melt etc.

However you may be able to double the light and have no problems, it's virtually impossible to guess, especially without additional info on your tank setup.

 

[Sarpijk]

It is a 60 litre tank with pressurised co2 and I follow EI ferts regimen. Originally I started the tank with just 24 watts. Soon I wanted more light and I upgraded to 48. The tank had its ups and downs while I was trying to figure out co2 and ferts. Last Christmas while reading a Ukaps post by Clive I decided to go back to 24 watts. Indeed green spot and bba vanished from my system and I had good growth from relatively easy plants. Now it seems to me that plants like L. Aromatica and hygro pinnatifida could use some extra light.

I now face the dilemma of either replacing my existing T5 bulb (which has been working for three years now) or add another bulb and double my lighting. I have also read Clive's post about T5s for being good as long as they light up. On the other hand I' ve read treads aboyt low light. I am torn now because I am not sure what to believe.

Anyway raising the lights fiture is not an option. I was thinking of letting my frogbit cover as much of the surface and I will also try to temporarily add some stems of plant like hygro polysperma in order to combat any algae.

 

[Mick.Dk]

It may help to think "CAR":
When you up your light, you hit the gas-pedal. This makes you go faster, but you will need more fuel. Ferts (incl.CO2) = fuel.
I think we all know, that a fast/sudden acceleration has an impact.............

 

[dw1305]

Hi all,

I was thinking of letting my frogbit cover as much of the surface and I will also try to temporarily add some stems of plant like hygro polysperma in order to combat any algae

I'd add the extra light, and up the plant mass. I don't worry too much about how much PAR I have, more light = more plants.

cheers Darrel

 

[Mick.Dk]

If you have access to Limnophila sessiliflora, this is one of the best "helping plants" (=plants bringing fast bio-mass) be it in a start-up phase or a sudden-change phase. This plant will tolerate high-/low light, added- /no added CO2......and adapt willingly to changes back and forth, of both.
It is a serious, fast grower too, making it so good as a "helping plant".
After getting your other plants adapted to new conditions, you can dismiss it, since it is really not that expensive.

 

[Sarpijk]

So starting today I will add a second light tube. I have decided to do so seeing that I have trouble growing some plants to grow lush and healthy. I have some stems of L. Sessiflora as per Mick's suggestions. Should I plant them or can I just float them in order to diffuse some light as well. I also have some frogbit which I am thinking of letting cover a good deal of the surface.