Advice for newbie

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
Hello all. I need your experience & advice as my head is exploding trying to figure out if my new (first ever) tropical freshwater aquarium has adequate lighting for my requirements.

I have purchased a Fluval Flex 123 litre aquarium

32.5 x 15.35 x 15.75"
(82 x 39 x 40 cm)

The provided lighting is a 21W 1450 lumen Aquasky LED light. I am completely lost in trying to calculate if this is sufficient lighting for plants that are deemed "Medium" difficulty to grow?

My shortlist of plants I wish to put in the aquarium are:

Red Myriophyllun
Hydrocotyle tripartita
Rotala 'Bonsai'
Eleocharis acicularis 'Mini'

Essentially I want to know if this setup provides sufficient lighting for these plants to grow? There is room for a second LED strip if needed. I have seen some online lighting calculators but the terms LUX LSI etc go over my head & they seem to be focused on non-LES Watt ratings.

thanks.
 
Last edited:

kilnakorr

Member
Joined
16 Mar 2020
Messages
208
Location
Denmark
In my opinion, yes, it's should grow your chosen plants without issues.
It's hard to say, as I can't really find much info on the unit.
You could try to get some PAR measurement by contacting the company.
 

Witcher

Member
Joined
15 Jan 2020
Messages
294
Location
London
I think you need at least 60W light for that height of the tank to have Myriophyllum and Rotalas (most of them, not only red or indica) growing ok, not sure about H. tripartita and Eleocharis.
 

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
Thank you. On reflection I hae re-considered my choices & chosen some more 'hardy' plant choices. Don't want to run before I can walk.
 

Simon Cole

Member
Joined
25 Dec 2018
Messages
469
Location
Buckingham
I can't say for certain but I have the smaller model:

I've got the 34 litre flex which comes in at 1900 lumens. It is totally unsuitable for my own aquascaping hobby because there is not enough light. Cryptocorynes grow but remain small. Micranthemum monte carlo forms a very weak and small-leaved spread. Rotalas including bonsai will grow very weak stems and these are hardly worth replanting. Heteranthera zosterifolia will straggle and just about cling on. Limnophila sessiliflora straggles up and does okay. Fissidens fontanus moss does okay. Light distribution is very poor and there is a hot spot formed by the curved glass, so planting at the back of that tank is not worth the bother. Most aquascapers corporately promoting these tanks rely upon heavy planting. The internal filter looks like a huge abstract piece of black plastic, which was the first thing we removed. Generally you don't need to worry very much about algae (even this seems to struggle). The glass also tends to be very thin.

The problem with these tanks is that the LED's do not have a bidirectional current converter, so effectively you only get half the lumens over time. They still appear as bright as a proper LED light to our eyes, and most people reviewing these tanks know nothing about electronics, or simply want to believe that an adapter is the same thing (or that so and so had this tank and posted a video etc). It doesn't matter. Likewise, I can tell you what the PAR should be and many people will measure this, but nobody bothers to check for LED flicker, meaning that even if you get a PAR metre and a reading (or have one supplied), that this will be meaningless too.

Personally I wouldn't even bother setting it up. I'd just sell it on.
 

jaypeecee

Member
Joined
21 Jan 2015
Messages
1,459
Location
Bracknell
The problem with these tanks is that the LED's do not have a bidirectional current converter, so effectively you only get half the lumens over time. They still appear as bright as a proper LED light to our eyes, and most people reviewing these tanks know nothing about electronics, or simply want to believe that an adapter is the same thing (or that so and so had this tank and posted a video etc). It doesn't matter. Likewise, I can tell you what the PAR should be and many people will measure this, but nobody bothers to check for LED flicker, meaning that even if you get a PAR metre and a reading (or have one supplied), that this will be meaningless too.

Hi @Simon Cole

My background is in electronics and I'm very interested in aquarium lighting. What you are saying is of interest to me. Perhaps you could expand on the last sentence above. Feel free to get as technical as you deem appropriate. And, if you think it may be better to do so, we can discuss this via PM. It's your call.

JPC
 

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
I can't say for certain but I have the smaller model:

I've got the 34 litre flex which comes in at 1900 lumens. It is totally unsuitable for my own aquascaping hobby because there is not enough light. Cryptocorynes grow but remain small. Micranthemum monte carlo forms a very weak and small-leaved spread. Rotalas including bonsai will grow very weak stems and these are hardly worth replanting. Heteranthera zosterifolia will straggle and just about cling on. Limnophila sessiliflora straggles up and does okay. Fissidens fontanus moss does okay. Light distribution is very poor and there is a hot spot formed by the curved glass, so planting at the back of that tank is not worth the bother. Most aquascapers corporately promoting these tanks rely upon heavy planting. The internal filter looks like a huge abstract piece of black plastic, which was the first thing we removed. Generally you don't need to worry very much about algae (even this seems to struggle). The glass also tends to be very thin.

The problem with these tanks is that the LED's do not have a bidirectional current converter, so effectively you only get half the lumens over time. They still appear as bright as a proper LED light to our eyes, and most people reviewing these tanks know nothing about electronics, or simply want to believe that an adapter is the same thing (or that so and so had this tank and posted a video etc). It doesn't matter. Likewise, I can tell you what the PAR should be and many people will measure this, but nobody bothers to check for LED flicker, meaning that even if you get a PAR metre and a reading (or have one supplied), that this will be meaningless too.

Personally I wouldn't even bother setting it up. I'd just sell it on.
Not what I wanted to hear obviously! The tank is unpacked & is being set up step by step, so I shall have to try my best and see what results.
 

Wookii

Member
Joined
13 Nov 2019
Messages
990
Location
Nottingham
Not what I wanted to hear obviously! The tank is unpacked & is being set up step by step, so I shall have to try my best and see what results.

I have a 60 litre (60 x 30 x 35) tank and use the Fluval Plant 3.0 which is 32W, and to be honest it isn't really enough for my tank. Growth is fairly slow at the substrate level, and the spread of the light across the tank isn't great. I suspect you will struggle with the Aquasky that is only 21 watt, in a tank that is larger and deeper than mine.

If you are set on using the tank as is - I would look to see if you can swap the light out for a better unit, and utilise the second empty slot you mention. Failing that stick to plants with very low lighting requirements.
 

Simon Cole

Member
Joined
25 Dec 2018
Messages
469
Location
Buckingham
@jaypeecee Alternating currents have sine waves, and on my model they are 60 Hz (60 cycles per second). LEDs require a minimum current, and when modulation occurs they turn on and off at the same rate as the frequency. This is called LED flicker. Typically this flicker has a 50% duty cycle. Which means that the LED is only on for 50% of the time. Dimmer modules are sometimes included by the manufacturer so that the frequency can be increased and the pulse width broadened. This has the effect of increasing the duty cycle, but it is rare to get beyond about 75% even at frequencies over 10 kHz (to speculate, this probably works because LEDs have a reaction time of about 300 ms and the peaks get closer together). The best solution has always been to provide direct current so that there is no modulation. Thus constant current drivers are preferred. The physical size of these components would be noticeable if they were included. Do you know what I mean. I can see what looks like a sealed dimmer module between the adapter and the light bar which is what is controlling the remote control lighting levels, colors and effects [through pulse width modulation]. This is better than nothing, but I could not honestly say that the lumen output assumed for each LED, will be achieved.

The problem with Par meters is that they cannot interpret LED flicker - they were designed for sunlight which has no modulation. The best option to check this would be an oscilloscope. I actually think that some of the other higher intensity LED units are ideal. They probably only include dimmer modules, but a 25% drop in efficiency has no real impact upon performance and this is factored into design. I would feel a lot more happy if Fluval could explain how they control their LEDs but somehow this is not mentioned in the specifications. I wonder why?

@KAB28 It's a nice tank. What annoyed me was the advertising: the box shows Alternanthera reineckii mini and Eleocharis mini (or something similar) growing away. You can tell that this has been photoshopped because the distinctive light hot spot is gone. There is no way this is achievable. Pektec on YouTube has one with two bars - and he would be the person to direct your questions towards. Nice chap and very helpful. You're going to have a lot of fun and then the opportunity to upgrade if you choose. The tank is actually quite cool. It just baffles me how low the lighting intensity is.
 
Last edited:

jaypeecee

Member
Joined
21 Jan 2015
Messages
1,459
Location
Bracknell
The problem with Par meters is that they cannot interpret LED flicker - they were designed for sunlight which has no modulation. The best option to check this would be an oscilloscope. I actually think that some of the other higher intensity LED units are ideal. They probably only include dimmer modules, but a 25% drop in efficiency has no real impact upon performance and this is factored into design. I would feel a lot more happy if Fluval could explain how they control their LEDs but somehow this is not mentioned in the specifications. I wonder why?

Hi @Simon Cole

Let's deal with PAR meters first. Control of LEDs is for another day.

I don't see a problem with PAR sensors/meters handling pulsed light from LEDs. A common interface circuit to a photodiode (inside the PAR sensor) is a transimpedance amplifier. By using the appropriate capacitor value across its output, it can be tuned to smooth the pulsed output voltage. That should handle the 'flicker' perfectly well. The likes of Apogee know full well that their PAR sensors/meters are used with LED lighting. I don't think you need to be concerned.

I'm not surprised that Fluval don't provide the information that you mention above. Firstly, it is proprietary information. Secondly, there is a possibility that they don't know! I'm not sure just how much design work Fluval or R C Hagen (the parent company) actually do themselves. We cannot rule out the possibility that the design of their lighting products is sub-contracted to A N Other company.

JPC
 

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
I have a 60 litre (60 x 30 x 35) tank and use the Fluval Plant 3.0 which is 32W, and to be honest it isn't really enough for my tank. Growth is fairly slow at the substrate level, and the spread of the light across the tank isn't great. I suspect you will struggle with the Aquasky that is only 21 watt, in a tank that is larger and deeper than mine.

If you are set on using the tank as is - I would look to see if you can swap the light out for a better unit, and utilise the second empty slot you mention. Failing that stick to plants with very low lighting requirements.
I am going to add a second light. They do make an Aquasky 33W 2260 lm version. They also do some plant specific lights, so I shall look in to that.
 

Simon Cole

Member
Joined
25 Dec 2018
Messages
469
Location
Buckingham
@jaypeecee You are right. It would need to give flicker measurement quantities, and/or compute the light intensity accordingly. It would be interesting to get a reading and see if this is a major factor.
 
Last edited:
Joined
17 Aug 2018
Messages
1,098
Location
-
To give you some confidence, this is what one aquasky can do it you choose low light plants..
 

Attachments

  • 2F6BD5B5-EAF9-4928-96A3-D77AC3CC068C.jpeg
    2F6BD5B5-EAF9-4928-96A3-D77AC3CC068C.jpeg
    93.9 KB · Views: 31

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
Thanks Matt. My plants have arrived, so today is the day I add substrate, plants & water. Happy days!

I shall then be doing a fishless cycle using Dr Tim's ammonia.
 
Joined
3 Jan 2016
Messages
376
Location
Woking, UK
The Tropica web site suggests the following ranges for lumens per litre:

10-20 lumens per litre - low light, easy plants
20-40 lumens per litre - medium light, medium plants
40+ lumens per litre - high light, difficult plants

Lumens are not the ideal measure for plants, but it’s usually the only measure you get with your lights, and equipment to measure PAR is expensive. A “lumens per litre” number assumes that your tank is a typical shape - for a deep tank you’d need more.

So the tank you have with its standard light is giving you about 11 lumens per litre. That puts you firmly in “low light” territory. Doubling that up with the light they’ve suggested will put you near the bottom of the “medium” range. Most plants will be okay, but some will probably not - especially at the bottom of the tank. I doubt you’ll be growing a carpet of HC “Cuba” or Glossostigma, for example.
 

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
Thanks Mike. My x2 Fluval Aquasky lights I have now fitted should give me 23 lum/l. I have purchased some allegedly low-light requiring plants:

Ludwigia Palustris
Ludwigia repens 'Rubin'
Hygrophila Siamensis 53B ( 1-2-Grow )
Bacopa Caroliniana ( 1-2-Grow )
Sagittaria Subulata ( 1-2-Grow )
Taxiphyllum 'Flame' ( 1-2-Grow )
Taxiphyllum Barbieri ( 1-2-Grow )
Marsilea Crenata ( 1-2-Grow )

Fingers crossed.
 

jaypeecee

Member
Joined
21 Jan 2015
Messages
1,459
Location
Bracknell
Thanks Matt. My plants have arrived, so today is the day I add substrate, plants & water. Happy days!

I shall then be doing a fishless cycle using Dr Tim's ammonia.

Hi @KAB28

Please be aware that doing a fishless cycle using ammonia at the same time as having plants in your tank can possibly lead to some complications. This is because both the plants and nitrifying bacteria will use the ammonia. To date, I have always completed a fishless cycle before adding plants. But you may not need to use bottled ammonia at all if you rely on the plants to consume this waste product from your fish. @dw1305 is an advocate of avoiding ammonia addition. Try to collect some more information before deciding how best to proceed.

JPC
 

dw1305

Expert
Joined
7 Apr 2008
Messages
10,954
Location
nr Bath
Hi all,
@dw1305 is an advocate of avoiding ammonia addition
I am, in fact I was just typing this when your message notification popped up.
I shall then be doing a fishless cycle using Dr Tim's ammonia.
Don't add any ammonia to the tank, it doesn't help "cycle" the tank and it probably increases the time before the tank becomes stable.

Planted tanks are never cycled in the way that tanks which are entirely reliant on microbial nitrification are, but that doesn't matter, plant/microbe nitrification is a lot more effective than microbe only biological filtration.

Have a look at <"Bedside Aquarium"> and <"Dr Tim Hovanec's comments"> (he is the "Dr Tim" of "Dr Tim's").

cheers Darrel
 

KAB28

New Member
Joined
22 Mar 2020
Messages
23
Location
UK
@JPC
@dw1305

Thank you both! I shall read through that. I have only got so far as placing the ADA Power Sand Advance & Amazonia Regular in to the tank so far.
 

Similar threads

Top