Fluorescent bulb dimensions

[foster53]

Are the true measurements of a Flo. bulb pin to pin, or is it just the length of the bulb itself? Need to replace the bulbs in my HO fixture, but not sure what actual length the new bulbs need to be. My current bulbs are 34" pin to pin.
Where do you all get your bulbs? Looking for 36" 6700K, and 10,000K 39 watt T-5 HO bulbs of good quality.

 

[fort384]

The actual dimension is off from the nominal dimension, but they are standard... so you will want to look for replacement bulbs for a 36" T5HO fixture.

Giesemann Powerchrome bulbs are regularly regarded as some of the highest quality bulbs you can use. A combination of a 36" powerchrome aquaflora and 36" powerchrome midday would be a great combo for a planted tank. Note that both of these bulbs will have an actual dimension of 34" pin to pin.

they are pretty widely available... marinedepot carries them both, as do a few other places.

Keep in mind that T5HOs have to be replaced every 6-12 months to maintain their effectivity.

 

[foster53]

The actual dimension is off from the nominal dimension, but they are standard... so you will want to look for replacement bulbs for a 36" T5HO fixture.

Giesemann Powerchrome bulbs are regularly regarded as some of the highest quality bulbs you can use. A combination of a 36" powerchrome aquaflora and 36" powerchrome midday would be a great combo for a planted tank. Note that both of these bulbs will have an actual dimension of 34" pin to pin.

they are pretty widely available... marinedepot carries them both, as do a few other places.

Keep in mind that T5HOs have to be replaced every 6-12 months to maintain their effectivity.

Thanks for the info. I have noticed that they seem to be mostly a standard length of 34"
I had actually decided to go with Giesemann. After some research, they seem to be the best quality.
Mine are at about a year old now, and I see a difference in plant growth, color, and also algae growth.