Solar meter 6.5 advice

[Andreotti10]

Hi
I have had my 2 Russian tortoises a year now. I quickly learnt this is the place for good advice

I’m obsessed with my 2 tortoises, they both live in separate 8x 4 houses and are very happy

I quickly learned 3 things are key to their happiness and health
-diet
-lighting
-temps

I’m good with food still trying to improve variation but ok

Temps are good each enclosure has 3 digital machines with probes telling me exactly the temps in all areas

I’ve always been bothered about lighting. I use the t5 bulbs.

Here’s a horror story when I bought my first tortoise the guy sold the enclosure too and mounted the t5 bulb to the side of the unit, poor henri was looking in to it

I was no expert then but I wasn’t comfortable. I rang the bulb technical support to be told the bulb should be minimum 30cm above his back. I adjusted this and he was much happier.

I continued to worry about the bulbs losing uv are they too high or low. So I was delighted to find Tom in a thread mention a solar meter 6.5. So after being ripped off for £260 from Amazon it arrived today!!!

It wonderful but I’m not quite sure what I’m doing.

My reading for henri is too high I think which means I will make bulbs higher
Right under the t5 bulb direct is 8

Then where the housing has a reflector a foot away is 3

Where he bask he’s around 4

Now I know why he never sits directly under the bulb

My other tortoise is 6 directly under so that’s an older bulb maybe why

Is there anyone really good on these Ferguson zones that can tell me what I should be exactly looking for

Tom thank you for what you do I have huge piece of mind knowing my tortoises are now getting uv and won’t get soft shells. Even if it’s too much I don’t know

 

[zovick]

Hi
I have had my 2 Russian tortoises a year now. I quickly learnt this is the place for good advice

I’m obsessed with my 2 tortoises, they both live in separate 8x 4 houses and are very happy

I quickly learned 3 things are key to their happiness and health
-diet
-lighting
-temps

I’m good with food still trying to improve variation but ok

Temps are good each enclosure has 3 digital machines with probes telling me exactly the temps in all areas

I’ve always been bothered about lighting. I use the t5 bulbs.

Here’s a horror story when I bought my first tortoise the guy sold the enclosure too and mounted the t5 bulb to the side of the unit, poor henri was looking in to it

I was no expert then but I wasn’t comfortable. I rang the bulb technical support to be told the bulb should be minimum 30cm above his back. I adjusted this and he was much happier.

I continued to worry about the bulbs losing uv are they too high or low. So I was delighted to find Tom in a thread mention a solar meter 6.5. So after being ripped off for £260 from Amazon it arrived today!!!

It wonderful but I’m not quite sure what I’m doing.

My reading for henri is too high I think which means I will make bulbs higher
Right under the t5 bulb direct is 8

Then where the housing has a reflector a foot away is 3

Where he bask he’s around 4

Now I know why he never sits directly under the bulb

My other tortoise is 6 directly under so that’s an older bulb maybe why

Is there anyone really good on these Ferguson zones that can tell me what I should be exactly looking for

Tom thank you for what you do I have huge piece of mind knowing my tortoises are now getting uv and won’t get soft shells. Even if it’s too much I don’t know

With my younger tortoises, I tried to get a reading of about 3.5 when placing the Solarmeter directly on the substrate under the center of the bulb and pointing it straight up into the light. Higher readings than that seemed to drive them away from the light because it was too intense. Also, if your bulb is 3 or 4 feet long, you will find that the readings at each end vary a bit from the reading under the center portion of the bulb, and one end is usually a bit higher than the other end.

With older tortoises (4 to 5 years old and up), I found that a reading of 4.0 to 4.5 was OK and did not bother them.

In case you need to know this, you will be able to vary the readings by adjusting the height of the bulb above the substrate.

 

[Andreotti10]

With my younger tortoises, I tried to get a reading of about 3.5 when placing the Solarmeter directly on the substrate under the center of the bulb and pointing it straight up into the light. Higher readings than that seemed to drive them away from the light because it was too intense. Also, if your bulb is 3 or 4 feet long, you will find that the readings at each end vary a bit from the reading under the center portion of the bulb, and one end is usually a bit higher than the other end.

With older tortoises (4 to 5 years old and up), I found that a reading of 4.0 to 4.5 was OK and did not bother them.

In case you need to know this, you will be able to vary the readings by adjusting the height of the bulb above the substrate.

This is great thank you very much.
It’s tricky as the unit is taller than the tortoise!!! But directly under the t5 bulb in the centre is now 7. You are right they don’t go directly under it. They tend to within the reflector area where it’s around 4 and are happy there. Il be moving the lights an inch higher

 

[Tom]

Great advice from @zovick

I would add that I only run my Arcadia HO tubes for a few hours mid day to simulate the UV spike that happens outside daily. There is never strong UV for 12 hours a day outside. UV levels build slowly and peak mid day and then drop off in the afternoon. When I first got my meter I though it was broken. I took it outside and pointed it directly at the hot sun at 4:30 pm and got a reading of 0.0. Same thing at 8am the next morning. Then I got 0.1 around 9 am, and by 11:30am it was up to about 5.

I rely on bright LED bulbs all day to may it look "sunny" and the UV tube kick on from about 11-2 each day. If I lived in a frozen winter kind of place where the tortoise was indoors over winter, I might run the UV just a little more.

 

[Andreotti10]

Great advice from @zovick

I would add that I only run my Arcadia HO tubes for a few hours mid day to simulate the UV spike that happens outside daily. There is never strong UV for 12 hours a day outside. UV levels build slowly and peak mid day and then drop off in the afternoon. When I first got my meter I though it was broken. I took it outside and pointed it directly at the hot sun at 4:30 pm and got a reading of 0.0. Same thing at 8am the next morning. Then I got 0.1 around 9 am, and by 11:30am it was up to about 5.

I rely on bright LED bulbs all day to may it look "sunny" and the UV tube kick on from about 11-2 each day. If I lived in a frozen winter kind of place where the tortoise was indoors over winter, I might run the UV just a little more.

Thanks Tom have you found a solution to the problem that the unit is taller than the tortoise.
I read one of your comments about digging a hole in the substrate but still it’s a couple of cm below his back. So I now have 6 directly under his lamp pointing direct. But the. Allowing for a dip below the sensor.

When I angle it at the tortoise height it’s around 4 which is where they seem to like

I guess the point of this equipment in truth is to ensure your tortoise is getting uv and exactly if you need a new bulb which really is priceless

And a lot of piece of mind

 

[zovick]

Thanks Tom have you found a solution to the problem that the unit is taller than the tortoise.
I read one of your comments about digging a hole in the substrate but still it’s a couple of cm below his back. So I now have 6 directly under his lamp pointing direct. But the. Allowing for a dip below the sensor.

When I angle it at the tortoise height it’s around 4 which is where they seem to like

I guess the point of this equipment in truth is to ensure your tortoise is getting uv and exactly if you need a new bulb which really is priceless

And a lot of piece of mind

If you don't point the meter straight up at the bulb, you are getting an incorrect reading. IE, the 4 is really probably a 6 and therefore still too strong for a small tortoise. I would recommend just standing the meter straight up under the light and going for a reading of 2.5 or so to 3.0 or so by increasing the height of the light away from the substrate.

 

[Andreotti10]

If you don't point the meter straight up at the bulb, you are getting an incorrect reading. IE, the 4 is really probably a 6. I would recommend just standing the meter straight up under the light and going for a reading of 2.75 or 3.0 by increasing the height of the light away from the substrate.

Yes you are right I will do exactly this. When i do that now it’s 6 which I know is still high so I will raise the lights. However the sensor is still 2 inches above the tortoise so the 6 is probably 4

I have to say it’s a bit of a silly design surely??

 

[Tom]

I have to say it’s a bit of a silly design surely??

I would agree. It can work for some situations, but the sensor should be on the flat part of the box, not the tall end.

 

[zovick]

Yes you are right I will do exactly this. When i do that now it’s 6 which I know is still high so I will raise the lights. However the sensor is still 2 inches above the tortoise so the 6 is probably 4

I have to say it’s a bit of a silly design surely??

Since light intensity varies inversely with distance, it is hard to say if the 6 at sensor height is actually a 4 at the height of your tortoise's shell.

I can tell you this from my experience over many years. You really need to have a standardized method of getting a meter reading which is reproduceable in any situation. Guessing what the reading might be at tortoise height is not something I would do personally. This is what I did:

When I used the meter, I went for a reading of 3.0 to 3.5 when the meter was stood straight up on top of the substrate directly under the center of the bulb. for my baby tortoises. If the reading taken in that manner was much higher than a 3.5, they would not stay under the light, but rather attempted to get away from it and stayed at the sides of their enclosure to be as far away from it as they could.

 

[Andreotti10]

Yes I agree as long as you are consistent.
You are also essentially guessing too, as your machine sits much taller than a baby tortoise.
But I know one of mine definitely prefers it at the sides where the uv level is lower so I have slightly raised the lights.

As Tom says I can’t believe they would design it so the tall part has to aim at the light!!

 

[Tom]

Yes I agree as long as you are consistent.
You are also essentially guessing too, as your machine sits much taller than a baby tortoise.
But I know one of mine definitely prefers it at the sides where the uv level is lower so I have slightly raised the lights.

As Tom says I can’t believe they would design it so the tall part has to aim at the light!!

Well their design works great if your tortoise is exactly as tall as the UV meter!

Digging through the substrate and resting the butt of the meter on the bottom of the enclosure gets you a little closer to tortoise shell height, and that is close enough for me.

@zovick has more experience that probably everyone else on this forum combined. I don't agree with him on every point on every subject, but he is almost always right, and he brings up a good point here. I aim for a level around 5-6 to simulate the high levels of mid day sun, but I only run my tubes for a 2-3 hours mid day. My tortoises are out and about during this time, but I'm going to watch their activity levels and behavior after reading these words from Zovick and see if they are avoiding the UV during this time. I may try raising the fixture to see if I can notice a difference at a little lower UVI reading.

This may also vary by species. My platynota tend to avoid mid day sun and are very crepuscular in their behavior. I have other species that are known to be sun lovers and bask more often. @zovick , Are you basing your observations on multiple species, or primarily radiata?

 

[Andreotti10]

Well their design works great if your tortoise is exactly as tall as the UV meter!

Digging through the substrate and resting the butt of the meter on the bottom of the enclosure gets you a little closer to tortoise shell height, and that is close enough for me.

@zovick has more experience that probably everyone else on this forum combined. I don't agree with him on every point on every subject, but he is almost always right, and he brings up a good point here. I aim for a level around 5-6 to simulate the high levels of mid day sun, but I only run my tubes for a 2-3 hours mid day. My tortoises are out and about during this time, but I'm going to watch their activity levels and behavior after reading these words from Zovick and see if they are avoiding the UV during this time. I may try raising the fixture to see if I can notice a difference at a little lower UVI reading.

This may also vary by species. My platynota tend to avoid mid day sun and are very crepuscular in their behavior. I have other species that are known to be sun lovers and bask more often. @zovick , Are you basing your observations on multiple species, or primarily radiata?

I’m fortunate and grateful to have both of your observations regarding this topic.

I’ve been watching both of mine and honestly already they have moved moved more directly under the lights and opposed to the sides where obviously the uv light is weaker.

I suppose this is the beauty about these meters, digital temperature probes etc it give us chance to really know what is going on in the enclosure.

I was spending too much time recording bulb change dates, wondering if they are still producing enough uv. Every time my tortoises went in to a hide I considered it could be the bulbs. We’re they too high, too low, we’re the bulbs hurting their eyes.

Probably the best £250 I have spent in terms of piece of mind

 

[zovick]

Well their design works great if your tortoise is exactly as tall as the UV meter!

Digging through the substrate and resting the butt of the meter on the bottom of the enclosure gets you a little closer to tortoise shell height, and that is close enough for me.

@zovick has more experience that probably everyone else on this forum combined. I don't agree with him on every point on every subject, but he is almost always right, and he brings up a good point here. I aim for a level around 5-6 to simulate the high levels of mid day sun, but I only run my tubes for a 2-3 hours mid day. My tortoises are out and about during this time, but I'm going to watch their activity levels and behavior after reading these words from Zovick and see if they are avoiding the UV during this time. I may try raising the fixture to see if I can notice a difference at a little lower UVI reading.

This may also vary by species. My platynota tend to avoid mid day sun and are very crepuscular in their behavior. I have other species that are known to be sun lovers and bask more often. @zovick , Are you basing your observations on multiple species, or primarily radiata?

@Tom Thanks for the (humiliatingly) kind words re my experience!

I am basing my observations primarily on Radiated Tortoises, but also have a good amount of experience with platynota. I did not feel that my platynota were crepuscular in habit, so perhaps a lower Solarmeter reading would change their behavior in your collection. Only way to know is to try it and observe any changes.

 

[Tom]

@Tom Thanks for the (humiliatingly) kind words re my experience!

I am basing my observations primarily on Radiated Tortoises, but also have a good amount of experience with platynota. I did not feel that my platynota were crepuscular in habit, so perhaps a lower Solarmeter reading would change their behavior in your collection. Only way to know is to try it and observe any changes.

Thank you. Try it, I will.