How long do lights *need* to be on?

[Gaina]

Hello All!

My tank (Fluval Roma 125) is now 6 months old and ticking over quite nicely, apart from the fact I'm still battling a bit of soft brown algae on the glass. My water parameters are fine so I'm thinking the solution may lie in reducing the amount of time my lighting is on. It was on for 5hrs (10am - 3pm) so today I've knocked it back to 4 hrs. Is this enough or could I knock it back some more?

Plants are as follows:

Amazon Frogbit
Bacopa Caroliniana
Echinodorus Bleheri
Echinodorus Granat
Cryptocoryne petchii
Cryptocoryne Wendtii Brown
Vallisneria Spiralis
Java Moss
Java Fern

I do think I need more plants (see HERE) but I'm still thinking my lighting schedule is not quite right.

 

[tam]

If it was me, I'd look at reducing the amount of light, rather than shortening the period it's on. Otherwise you are going to end up not being able to look at the tank as the lights are always off!

Have you had the frogbit long? As that grows across the surface it will reduce the intensity of light to plants underneath - you could consider other floaters too. Raising the light or diffusing it with something semi-transparent underneath works too.

 

[alto]

As I recall, lighting is the stock LEDs that come with the AIO kit - 10watt but no idea on lumens or PAR
I think you mentioned 31LEDs so at most 0.3watt, even top of the line 0.3w LEDs won't deliver much intensity through a 50cm water column (& I suspect these are very basic 0.3w LEDs given the lack of technical information on Fluval website, no mention of internal reflector lens, so likely there isn't one)

Given those assumptions, I'd not decrease photoperiod (unless tank receives significant ambient (sun)light)

Sounds like diatoms/brown algae on the glass, this isn't all that light sensitive (even a tank blackout won't have much effect), instead focus on plant health & tank maintenance (brush algae off leaves etc if you've no algae crew doing that)

I would not consider any light period less than 4 hours
I'd recommend 5-6h minimum

 

[Gaina]

If it was me, I'd look at reducing the amount of light, rather than shortening the period it's on. Otherwise you are going to end up not being able to look at the tank as the lights are always off!

Have you had the frogbit long? As that grows across the surface it will reduce the intensity of light to plants underneath - you could consider other floaters too. Raising the light or diffusing it with something semi-transparent underneath works too.

Hi Tam

Yes, I've had the Frogbit a while and there's a good covering of it on the surface (it grows so well I have to take a bit out occasionally!).

I was actually thinking about changing the bog-standard light that came with the aquarium for one of the fluval plant ones.

As I recall, lighting is the stock LEDs that come with the AIO kit - 10watt but no idea on lumens or PAR
I think you mentioned 31LEDs so at most 0.3watt, even top of the line 0.3w LEDs won't deliver much intensity through a 50cm water column (& I suspect these are very basic 0.3w LEDs given the lack of technical information on Fluval website, no mention of internal reflector lens, so likely there isn't one)

Given those assumptions, I'd not decrease photoperiod (unless tank receives significant ambient (sun)light)

Sounds like diatoms/brown algae on the glass, this isn't all that light sensitive (even a tank blackout won't have much effect), instead focus on plant health & tank maintenance (brush algae off leaves etc if you've no algae crew doing that)

I would not consider any light period less than 4 hours
I'd recommend 5-6h minimum

Thanks Alto. My tank is facing away from my window, but my room is quite bright on a sunny day (though I am not a fan of bright light so I have black out blinds which I tilt in the afternoon just before the sun comes round). I think I might actually set the timer for 6 hours as I these plants grew much more vigourously in my previous (smaller) tank.

I have just been reading up on diatom algae and from the photos I've seen that's exactly what it is - I knew in the back of my mind I'd read this was a normal part of the 'settling in' period for a new aquarium, but it's good to have it confirmed.

As far as algae eaters go, I've got 7 Amano shrimp and they're doing a great job of keeping the leaves and rocks clean. I've found my rasbora are partial to the algae as well! I really wanted some Otocinclus catfish anyway, so I'll definitely be adding some to the tank. I did have nerite snails but my water isn't hard enough for them in this new aquarium (7Gh). They're also prone to dying when they go up-side down and they're little ammonia bombs when that happens - I'd never had ammonia problems until two died, which lead to me upgrading my tank slightly sooner than I had planned. At least it's pretty obvious when a shrimp or fish has turned its toes up! haha

As I said to Tam, I'm considering changing my lighting to the 'Fresh and Plant' light from fluval which has the following spec:

Wattage: 59 W

Lumens: 4.250 LM

Colour temperature: 7500K

I'm now off to change my light timer! Thanks for the advice.

 

[tam]

The Fluval looks good doesn't it, I've been considering it recently. The benefit over your current light is you can control the intensity. So you can have it on for a long period with low light or a short period with higher light.

 

[Gaina]

The Fluval looks good doesn't it, I've been considering it recently. The benefit over your current light is you can control the intensity. So you can have it on for a long period with low light or a short period with higher light.

Yep, I think that's sold it to me.

 

[Gaina]

Just a quick update. I am now running my lights an extra hour and have noticed significant plant growth (the echinodorus bleheri had previously been sluggish, which I knew wasn't right cos it was an absolute thug in my other aquarium! ).

Algae is manageable, and certainly hasn't got any worse.