What Is The Difference

[markandhisfish]

what is the difference between t8 and t5 lighting and is t5 really worth the extra cost?

 

[RadaR]

T5s are amazing.
T8 have a diameter of 1", whereas T5 have a diameter of 5/8th”.
T5s are more bright and more intense. Almost double than a T8 I would say.
Remember though, more light means more demand for CO2 and nutrients. If these cant be provided in enough quantites then upgrading lighting isn't a good idea.

 

[markandhisfish]

right i see thanks. so in my 4x2x2 im running 1wpg t8 ( well just over 1 wpg im running 3x38w tubes ) and not using co2, so im guessing that t5s wouldnt be a smart move for my needs?

 

[RadaR]

right i see thanks. so in my 4x2x2 im running 1wpg t8 ( well just over 1 wpg im running 3x38w tubes ) and not using co2, so im guessing that t5s wouldnt be a smart move for my needs?

Correct.

 

[markandhisfish]

great . thanks for your help

 

[SuperColey1]

T5s are more bright and more intense. Almost double than a T8 I would say.

In fact this is not true. T5s are about the same as T8s. They are however more efficient.

T5HO are almost double the power input as a T8 but are not as efficient as either T5 or T8. I would suggest that their output per W used is also not as much as the equivalent T8 or T5 however that of course would mean more tubes for the same wattage.

AC

 

[markandhisfish]

T5s are more bright and more intense. Almost double than a T8 I would say.

In fact this is not true. T5s are about the same as T8s. They are however more efficient.

T5HO are almost double the power input as a T8 but are not as efficient as either T5 or T8. I would suggest that their output per W used is also not as much as the equivalent T8 or T5 however that of course would mean more tubes for the same wattage.

AC

errrrm now im really confused

 

[jacko32]

T5s are more bright and more intense. Almost double than a T8 I would say.

In fact this is not true. T5s are about the same as T8s. They are however more efficient.

T5HO are almost double the power input as a T8 but are not as efficient as either T5 or T8. I would suggest that their output per W used is also not as much as the equivalent T8 or T5 however that of course would mean more tubes for the same wattage.

AC

errrrm now im really confused

me too i have 2x39w T5HO does this mean i have 78w or is it less with T5HO grrr confused

 

[steve...c]

T5s are amazing.
T8 have a diameter of 1", whereas T5 have a diameter of 5/8th”.
T5s are more bright and more intense. Almost double than a T8 I would say.
Remember though, more light means more demand for CO2 and nutrients. If these cant be provided in enough quantites then upgrading lighting isn't a good idea.

i just checked my bulbs on my second hand tank the tank was 6months old, i have 2 t5 plant pros, whats this about co2 and nutrients? im a complete beginner, sorry for my ignorance.

 

[markandhisfish]

im confused as well now i thought it was more simple than that. for example i have a 100 gallon tank with 3 38w t8 tubes . i assumed that means that 3x38 = 114w which in turn means just over 1 watt per gallon. is that right or am i missing something?

 

[steve...c]

im confused as well now i thought it was more simple than that. for example i have a 100 gallon tank with 3 38w t8 tubes . i assumed that means that 3x38 = 114w which in turn means just over 1 watt per gallon. is that right or am i missing something?

oh is that how it works, havent check my watts will do now tho.

 

[markandhisfish]

dont take my word on it , im just as confused as you, i just assumed you took your total watts , divided it by your gallons and that gave you your wpg?

 

[RadaR]

Check out these links.

Minimum Light Threshold

Lighting

 

[steve...c]

dont take my word on it , im just as confused as you, i just assumed you took your total watts , divided it by your gallons and that gave you your wpg?

yeah well putting it like that makes sences to me ha, altho mine dont have the watts on them

 

[SuperColey1]

Not that light is my obsession but I'll clear it up a little for you

Firstly the 2 articles above are by a well respected and well thought of experienced man in the hobby. Indded I respect him completely however.........

...........This sentence on the second one (right at the beginning) To have a successful planted tank you must have light and quite a bit of it makes his article fall down in an instant which is a surprise.

Couple that with the use of Lumens and Lux to calculate light in the first article and it shows that it may be an old article or using some old knowledge.

So on to the spiel:

First Article:
Lumens and Lux are not measurements of light. They are measurements of how bright the light looks to the human eye. In other words you could have a pink tube with less lumens and a green tube with super high lumens. Even though they are the same Watts the pink tube looks much much dimmer. However here is the important part. The 2 tubes most likely are pretty similar in actual output of light - Photosynthetically Active Radiation (PAR)

Plants do not care what we see. We can have lights 10x more the brightness but they are interested in the PAR or to be more precise the PUR (Photosynthetically Usable Radiation)

We use WPG because its pretty simple to gauge. W is printed on the tube and box and we know the size of our tank. Therefore we can guesstimate how much light we are putting over the tank. How much is reaching the target is another matter which involves eficiencys, quality of reflectors, positioning etc. very complicated. To use Lumens and Lux leads us down the wrong path as we are not interested in what we see apart from the appearance (aesthetic reasons only.) PAR meters (Quantum meter)are pretty expensive. That is why we use WPG. No outlay and reasonable guesstimate of what we have.

First Article
To have a successful planted tank you must have light and quite a bit of it: Now it is not just I that would poo-poo this idea. In fact Llj and many others have not just succesfully kept planted tanks under low light but have outperformed highlight tanks in many cases.

You can stick 3WPG over a tank but have it badly positioned and my 1WPG will outperform it. Couple that with highlight making it much harder to keep CO2, circulation, nutrient all up to scratch then it more often than not leads to disaster.

I would suggest to people that 1WPG is a great starting point. Access things and move up if desired after you learn about planted tanks. In basic stick with the lights that come with the tank and then after you learn how to keep a planted tank then acces the situation.

On to T5/T8/T5HO. For this I will use 2 abbreviations:

NO = Normal Output
HO = High output

Basically your standard tube is a T*NO. The T* being the diameter and the NO being normal output. Thats pretty simple. Now its a waste of time, money, ink etc to tell you something is normal so they very rarely but NO on their tubes/boxes.

HO means that the tube gives out much more than the standard. They require ballasts to match so you can't just swop a 2ft T5 for a 2ft T5HO. It will just run the HO at whatever the ballast is capable of....in other words exactly the same as the NO was running at. This is a common problem in that people buy a 20W T8HO thinking it will be brighter than the 18W T8NO it replaces. However they will both be the same because the ballast will be 18W (or as I discovered in many cases 15W!!!!!)

Now onto the second rant......

T5(NO) and T8(NO) are about the same watts for the same lengths of tube. You can't get them exact same lengths but they are approximately the same watts per inch of tube.

T5(HO) and T8(HO) are not the same watts for the same lengths og tube. The T5HO is normally about a 35% more powerful than its NO equivalent and the T8HO is normally about 10% more powerful.

Some important details are missed out by 'T5HO lovers':

- T8NO and T5NO will outperform T5HO in terms of efficiency as long as you use electronic ballasts (T5HO always do)

- T8NO and T5NO will provide more lumens per watt and more PAR per watt than T5HO.

Why then do people think T5HO is better? Because it looks better and means less tubes. T5HO penetrates better too.

SO what is the problem? If we work on Lumens, Lux, etc we are working on the same reasoning as something looking better and assuming it is. What we have been discovering over the past couple of years is that with better positioning so that we can spread light better that we can reduce the light whilst maintaining growth.

Think about it:

We get 1 x T5HO which is 30W and put it over our tank. The area directly below will be superpowered in intensity. The front and rear of the tank will be much much less, may not look less in terms of what we can see but believe me the differences are incredible.

Now take 2 x T8/T5 15W....Still 30W and put it over the tank. We now can space them a third from the rear and a third from the front. We now spread the 30W out a little better. If anything we now have more actual light for the same power usage because the NO tubes are more efficient (on electronic ballasts.)

We found this out when we started experimenting with LEDs. Because they are small point source units they have to be spaced out in a gridlike pattern. All of a sudden we were getting great results. This was when we started testing like mad with PAR meters MH v LED v Flouro and started to link the spreading of light with being able to reduce the power input.

At this stage I managed to reduce my flourescent input down to 0.9WPG and it was still a very fast growing tank. Moving onto LED I have managed to get down to 0.6WPG. Still a very fast growing tank and very very bright

My tip : Before switching out those T8s for some super dooper T5HOs that are the DBs think seriously about your goals. If you are intending to move into reef and give up plants they may suit your goal but if you are staying with plants it kind of defeats the object. Better to keep the T8s and add some more than to get the T5HOs for less efficiency, less light and less coverage

AC