Tropical Fish Keeping banner

New double T5 HO and CO2?

4K views 20 replies 5 participants last post by  Byron 
#1 ·
I'm wondering after it was brought up in a different discussion.....
I have a 34g soon to be heavily planted tank, Currently using a t8 15watt but upgrading (as soon as the bulbs arrive) to a double T5 HO 24watt light.
It was brought up that i need strong light with a CO2 system, Will it work with this T5? It will be a tetra CO2 optimat setup.
 
#2 ·
The current consensus on forums that discuss pressurized CO2 and lighting seems to be that medium or medium-high light is better than "high" light. A slightly reduced amount of light gives more "oops" room regarding algae and CO2 levels. From my reading, most folks using pressurized CO2 have, at some time or other, killed their fish by using too much CO2. Using less light allows lower CO2 levels and thus, a larger safety margin while still increasing plant growth and reducing algae issues.

Two T5HO bulbs mounted just at the top of the tank provides light levels that are "too high" light, even with CO2, on an 18" depth tank. I'm not familiar with the dimensions on a 34 gallon.
 
#3 ·
The main reason im going high light is to have a lot of floating plants, i did it before and all the plants below it died due to low light. So the light is not going to be too intense i believe.
 
#4 ·
Removing a portion of floating plant's every so often so that light can reach bottom plant's is what most folks do.If you let floating plant's cover the surface,then yes plant's below will suffer.
You can try the light, but I suspect Algae and lot's of it will be the result unless you raise the light fixture up off the tank 8 inches or more, or cut a piece of aluminum window screen to fit under the light if it is to rest on the glass.(may need to double it)
Co2 plus high light,, will place a demand from plant's for more nutrient's both macronutrient's, and micronutrient's.(more than is found in most supplement's)
In the absence of these on regular basis, plant's in my view won't perform much better than simple low tech,low light tank,with weekly addition of product such as flourish comprehensive which you may already be using.
 
#5 ·
Even increasing the light won't necessarily be sufficient. The transmitted light (light passing through the floating plant's leaves) will not be the proper wavelength for photosynthesis to be optimal in your rooted plants. Most folks, as 1077 suggested, prune back their floaters. I try to keep mine at about 25-40% of the total water surface. I'm finding that 25% works best for my tank.
 
#6 ·
I'll be still giving the light a bash (cost a lot) for a while, see how it goes, if not i'll downgrade back to my t8. After a conversation with byron a while back we settled on t5 being a good idea with my tank, so much confusion in the aquarium world!
 
#7 ·
T5 is a good idea compared to T8. The issue here is not the bulbs you are using its the amount of light. You are switching to a more efficient bulb type while at the same time increasing wattage. A T5 HO produces a lot more light per watt then a T8. You originally had 15 watts of a T8 bulb. You are switching to a fixture that can produce 48 watts of T5 HO lighting. Your light increase from this switch is easily 5 times what it was before if not more. Its not the fixture itself that is the problem its the amount of light you are putting over the tank. A single T5 HO fixture that could run 24 watts would of been a better choice.
 
#8 ·
Agree, and since my name came up;-) I would remind you that I did suggest a single tube T5 as being ample. Dual-tube T5 is a lot of light over any tank (relatively speaking) and in my opinion not advisable without high-tech.
 
#9 ·
I struggled very badly with finding a single T5 fixture, the single fixture byron found (yes your name again :)) was only available in the states and i'm in the uk, It does say that my double fixture is fine to only use with a single bulb. Think i should just do that for now?
 
#10 ·
If the fixture will light with just one tube in it, fine. Some won't, but some will, it depends how they are wired.
 
#11 ·
Unless you are using CO2, you absolutely only need to run one bulb, even then one might work very well! Even with CO2, you'll still be in the "too high" light range using 2 T5HO bulbs unless you use some screening to reduce the intensity.
 
#12 ·
I have a thick transparent plastic lid between the light and the water surface, and (if my plants EVER arrive) I will have some gorgeous red floating plants. But I think for now i will only install the one bulb if it works, the guy i'm getting the bulbs from charges a fortune and he doesn't even have one of them i ordered in stock!
 
#14 ·
yeah there specifically for growing plants :D I've done my research first no worry haha.
 
#15 ·
Ok so my entire T5 purchase has backfired, cannot get hold of the bulbs anywhere and the person i was buying them from has ran out of them also. So what im thinking, my light is far too weak that i have still.
Double or single T8 20w? And Co2 or no Co2?
 
#16 ·
First, let's back up and ascertain exactly what you have now. I know it is a 35g tank, but what is the length? And you have a single T8 tube, again what is the length of the tube itself? These two measurements will tell me what you now have, or have the capability to have.

Second point, what sort of plant tank do you want? The majority of aquarium plants will grow fine without added CO2 diffusion. It you want a tank either like the Takashi Amano style, or one like what is known as the Dutch style [mainly plants, fish are very secondary and often not even present], or you want to propagate plants that are high-light, CO2 plus more light will be needed. But if you want a fish tank with good plant growth where the fish are primary and the plants are secondary, you do not need CO2 or higher light.

The issue is always balance; light and nutrients (of which CO2 is merely one) must be balanced at whatever specific level you want for your purpose.

Byron.
 
#17 ·
Ok its 30" long, i currently have an 18" 15w T8, The plants i have are 1 amazon sword, 5 red ivy, 5 large ambulia, some bunches of dwarf hairgrass just added trying to make a carpet, 1 bacopa and one cryptocoryne. Flame moss, Java moss, and i have 25 creeping jenny cuts and some riccia coming.

I apologise for the picture quality, taken on my cell phone. But this is basicly what i have now. Freshwater aquarium Aquarium decor Aquarium Aquarium lighting Organism

I will be filling out the back and the corners with creeping jenny.
Thought it would be easier just to list everything i had or will be having. If people know about each plant, please feel free to comment on their care also :) I feel like a noob with planted tanks.
 
#18 ·
And i forgot to add not all the creeping jenny will be going in this tank, im also using it to give the clawed frogs some live plants.
 
#19 ·
An 18-inch T8 tube over a 30-inch tank is cutting it close. I have a 24-inch tube over my 30-inch 29g and it works fine, although stem plants (requiring higher light) would probably struggle or not even last. The colour hue in the photo suggests this is one of the fish or plant type tubes, and they have significantly less intensity than the full spectrum/daylight type which is another detriment [unless the photo hue is the camera and not the actual light].

A single T8 with a 30-inch tube would probably work, and this would mean a glass cover for the tank with a 30-inch fixture. Most hoods for 30-inch tanks have 24-inch fixtures I believe, over here (NA) anyway. Or, a notch up, would be a dual T8 24-inch tubes which would be more likely to satisfy your stem plants and substrate plants which are all higher light requiring. Or a single T5 tube which we previously discussed and I gather is unobtainable in the UK.

There is also the LED fixtures, though so far I have only seen these over smaller tanks, max 20g. On larger tanks there would likely have to be a lot of LEDs to provide adequate light. And they are very expensive, like double the cost for a single fixture, at least over here. As you are in the UK, I believe Practical Fishkeeping is or had a series on planted tank lighting, authored by George Farmer who is very knowledgeable. Might want to track that down. I was browsing through I think the September issue last week and saw this mentioned; don't have the issue myself to check.

Byron.
 
  • Like
Reactions: Limeylemon
#20 ·
I was looking at a double t8 24 inch, very easy to get hold of and my lfs has thousands of bulbs, T5 is such a headache over in the uk. i'm staying away from it for now, until I have the space for the tall tank i want then maybe. Thanks for the advice there. Do you think the stem plants will survive for now? can't upgrade for another 2-3 weeks.
 
#21 ·
Maybe; let's hope so.:)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top