What is the ideal amount of light for a new 70L tank?

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
I'm in the process of setting up a new 70 litre (60 x 35 x 40) tank for the first time after 16 years away from the hobby. The tank will be fully CO2 and EI dosed.

Whilst most of the set-up will utilise kit I already have, the lights will be new, so out go my old metal halides, in favour of cooler and safer (the tank will be in my sons bedroom) LED's.

The light I have ordered is the 32W Fluval Plant 3.0 - I love that this can be programmed for a full day/night cycle simply using my phone - something that took multiple lights and numerous timers on my tanks of old.

However, what I'm struggling to determine is what the correct level the light should be at - particularly for the set-up phase where the plants will be growing in.

The Fluval Plant 3.0 is specc'd at 2350 lumens, and reportedly has allegedly a PAR value of around 100 at 300mm and around 70 at 450mm.

Is this too much for a tank startup, and should I be looking to reduce the intensity?

Also, what I should I set the initial photo period at - I see recommendations from 6 hours all the way up to 12 hours?

Any suggestions would be welcome.
 

jaypeecee

Member
Joined
21 Jan 2015
Messages
1,420
Location
Bracknell
Hi @Wookii

You have raised the $64,000 question! I couldn't find any reference to PAR at:

https://www.fluvalaquatics.com/us/plant-spectrum/

But, I am in a hurry - so please correct me if I'm wrong. Furthermore, the information presented is odd, to say the least. The primary colours of light are red, green and blue. Yet, one picture shows sliders for pink (!) and blue. Where's the green? And the spectrum shown is lacking in red light around 650 nanometres.

Just my initial thoughts.

JPC
 

alto

Member
Joined
24 Dec 2014
Messages
5,918
Not one of my favourite lamps but perhaps 3.0 has addressed previous design flaws ... it’s “value” rather depends on local cost/warranty
Regardless it should provide sufficient light for an 30-40cm tall aquarium, just check for shaded areas before you commit to a scape design

Cory at Aquarium Coop has done review videos on various versions of this light (no idea how the UK vs US versions differ) including some rough PAR measurements (view qualitatively) ...
more on this at
plantedtank.net
 

Tim Harrison

Super Moderator
Staff member
Joined
5 Nov 2011
Messages
7,787
Location
UK
Aside from all the technical mumbo jumbo, I'd just start on 50% intensity for 6hrs a day, a least for the first week and gradually increase it to around 60-70% intensity by 5% a week thereafter. Then see how you go at that light intensity.

As I'm sure you can remember it's a game of balancing the requirements of the plants against those of algae; most folk use way too much light which often favours the latter particularly if you're inexperienced or using a new light. If you want still more intensity increase by 5% per week, and watch for signs of nutrient deficiency and algae.

I usually wait till the plants have established and are growing well before gradually increasing the photoperiod to 8 hrs a day. By then the tank should have enough biological stability and wriggle room to absorb some mistakes. For most of us there is little point increasing the photoperiod beyond 8 hrs, since the plants won't benefit much but algae undoubtedly will.
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
Sorry guys, I wasn't getting notifications from this thread for some reason . . . I'll sort replies now.
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
The correct level of light depends on the plants you'll keep in your tank but as a rule of thumb I'd say 1W/L no matter if it's HT or not.

And I've never cared about initial photo period (and initial intensity of light) - I keep it at full power for 8 hrs.
Thanks - is that 1W per Litre based on LED or T5's though?
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
Hi @Wookii

You have raised the $64,000 question! I couldn't find any reference to PAR at:

https://www.fluvalaquatics.com/us/plant-spectrum/

But, I am in a hurry - so please correct me if I'm wrong. Furthermore, the information presented is odd, to say the least. The primary colours of light are red, green and blue. Yet, one picture shows sliders for pink (!) and blue. Where's the green? And the spectrum shown is lacking in red light around 650 nanometres.

Just my initial thoughts.

JPC
The PAR rating I saw on another forum from someone who has called Fluval and ask for that data. It could be baloney, but I have no reason to question it as such.

I believe the Red and Blue LED's supplement white LEDs - obviously the main component of white is green, so I think the green is covered.

Good point on the red on that graph. I have the unit here now though (it was delivered this morning) and it's certainly seems capable of producing a colour temp with plenty of red in it.
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
Not one of my favourite lamps but perhaps 3.0 has addressed previous design flaws ... it’s “value” rather depends on local cost/warranty
Regardless it should provide sufficient light for an 30-40cm tall aquarium, just check for shaded areas before you commit to a scape design

Cory at Aquarium Coop has done review videos on various versions of this light (no idea how the UK vs US versions differ) including some rough PAR measurements (view qualitatively) ...
more on this at
plantedtank.net
Thanks for the feedback. It's value to me is the automation and flexibility to be honest. To my fault I haven't really shopped around to much to look at alternatives. Would you suggest any other models?
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
Aside from all the technical mumbo jumbo, I'd just start on 50% intensity for 6hrs a day, a least for the first week and gradually increase it to around 60-70% intensity by 5% a week thereafter. Then see how you go at that light intensity.

As I'm sure you can remember it's a game of balancing the requirements of the plants against those of algae; most folk use way too much light which often favours the latter particularly if you're inexperienced or using a new light. If you want still more intensity increase by 5% per week, and watch for signs of nutrient deficiency and algae.

I usually wait till the plants have established and are growing well before increasing the photoperiod to 8 hrs a day. By then the tank should have enough biological stability and wriggle room to absorb some mistakes. For most of us there is little point increasing the photoperiod beyond 8 hrs, since the plants won't benefit much but algae undoubtedly will.
Thanks Tim, that makes sense and sounds like a plan. Triggering a massive algae outbreak is what I'm hoping to avoid - though I'm under no illusion that algae wont appear somewhere at some point, and to be fair I consider it part of a natural aquatic environment as long as its not too unsightly. At the same time I want to ensure I have sufficient light for the carpet plants to establish . . . a balancing act like you say.
 

Tim Harrison

Super Moderator
Staff member
Joined
5 Nov 2011
Messages
7,787
Location
UK
A lot of scapers use the TwinStar 600s series coupled with this inexpensive controller including myself. The light is relatively inexpensive and comes in tank mounted or pendant form, and has an amazing colour rendition that makes the colours of plants and critters pop.

The Twinstar light in use over NatureScape, on at 60% intensity and photoperiod 6 hrs/day. The carpet is MC...

48161889791_c36691ab93_b.jpg
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
A lot of scapers use the TwinStar 600s series coupled with this inexpensive controller including myself. The light is relatively inexpensive and comes in tank mounted or pendant form, and has an amazing colour rendition that makes the colours of plants and critters pop.

The Twinstar light in use over NatureScape, on at 60% intensity and photoperiod 6 hrs/day. The carpet is MC...

48161889791_c36691ab93_b.jpg
Thanks for the links Tim. That is a beautiful looking tank! What is the size?
 

Wookii

Member
Joined
13 Nov 2019
Messages
716
Location
Nottingham
The video. ( i was suspecting it to be a low tech tank, it being in your son's bedroom)
No, I have much of the kit for a high tech set-up from my previous tanks, and most of it can be store neatly under the tank so its not an issue that its in his bedroom.
 

Similar threads

Top