Help me understand my Par readings please? Should I upgrade lights?

[vdubers]

Hi all. So I’ve got a shipment of some acropora coming in. Most of my stuff has been doing really well and I have a few spots on my centre rock to give acros a proper go.

My current lighting is a pacific sun pandora LED t5 combo with four 4ft t5 tubes and three led pucks. My lights are set to 95% intensity at peak on one of the pre built lighting scenarios.

On the top of my rock I have what looks like a garf bonsai and some sort of stag acro growing well as well as some easier montipora.

Under that I have some stylophora and another stag acro and I think a pocillopora.

What surprised me was I got my par meter (itc par wise) out and measured par right at the top and was only getting around 150 par peak.

In fact just above the water line in the air directly under the centre led puck 12 inches away I only get 350 par!

Down with the stylos and the other stag I’m getting 70ish par.

All my reading suggests that this is too low levels of par for acropora but the ones I do have seem to be doing ok now. They weren’t always but lighting hasn’t changed and I think this was more down to nutrient issues.

Tldr: Not whether I need to upgrade my lights to get more par or whether the par meter is wrong?

Thanks for reading

Edited to add in photos as I forgot originally

 

[Subsea]

Let’s assume the PAR meter is correct, so what.

Do you believe in recognizing bioindicators as reliable? If your corals are displaying well why do you need higher PAR?

PS: If you don’t believe your PAR meter, bring it to a system with known values and see what yours read.

 

[vdubers]

Let’s assume the PAR meter is correct, so what.

Do you believe in recognizing bioindicators as reliable? If your corals are displaying well why do you need higher PAR?

PS: If you don’t believe your PAR meter, bring it to a system with known values and see what yours read.

I see what you’re saying. I am getting better polyp extension on the stag frag that is higher up but I think this is more a flow thing?

I guess even though things are growing there is that part of me that wonders if they could be growing better and light is the limiting factor.

 

[Subsea]

I see what you’re saying. I am getting better polyp extension on the stag frag that is higher up but I think this is more a flow thing?

I guess even though things are growing there is that part of me that wonders if they could be growing better and light is the limiting factor.

So, experiment with more lighting. In doing that, you should have the option of running intensity < 95%

I perused your threads and noticed you have several systems, which tank is this?

 

[vdubers]

So, experiment with more lighting. In doing that, you should have the option of running intensity < 95%

I perused your threads and noticed you have several systems, which tank is this?

Sorry I should have said. This is my current tank which is a 7ft 650 litre mixed reef. I plan to only have acros in the middle though. The majority of the tank is LPS and all are doing good at the moment. Increasing intensity to 100% is an option I could try but I don’t think it will help much. I might see if I can figure out a way to add some supplemental lighting just to the middle section.

 

[goosemans]

Did you set your meter to “under water” mode?

 

[DanyL]

The PARWise is downplaying the readings compared to the Appgge everyone are comparing with.

If I remember correctly, the multiplier telegraham came up with was 1.26 (verify this, because it’s from my memory).

This makes your 150 reading into 189 - many SPS corals will grow just fine, but it is on the low side.

 

[DanyL]

Did you set your meter to “under water” mode?

Very good point, and a common mistake.

 

[Subsea]

“Increasing intensity to 100% is an option I could try but I don’t think it will help much. I might see if I can figure out a way to add some supplemental lighting just to the middle section”

Most equipment is best operated at 80% full power.

For supplemental lighting in the middle section, you have many options. Have fun with it. I have used submerged accent night lights.

 

[eggie]

Any brands for the T5 ?

 

[Mr. Mojo Rising]

How long have you had your sps and are they growing? Are they basing out and showing white tips at the ends where it should be growing? If you see growth then the light is sufficient.

If you got them 6 months ago and they look today exactly the same as 6 months ago with no growth at all, then you need to turn the lights up.

 

[vdubers]

Did you set your meter to “under water” mode?

Thanks I ran to check but sadly yes it was already on underwater mode.

The PARWise is downplaying the readings compared to the Appgge everyone are comparing with.

If I remember correctly, the multiplier telegraham came up with was 1.26 (verify this, because it’s from my memory).

This makes your 150 reading into 189 - many SPS corals will grow just fine, but it is on the low side.

Ah good to know I will have a search. I did suspect something like that with the T5s as it reads lower than others reported with their t5s.

Very good point, and a common mistake.

Yeah for sure I think I made this mistake the first time I used it.

“Increasing intensity to 100% is an option I could try but I don’t think it will help much. I might see if I can figure out a way to add some supplemental lighting just to the middle section”

Most equipment is best operated at 80% full power.

For supplemental lighting in the middle section, you have many options. Have fun with it. I have used submerged accent night lights.

Thanks submerged lights would actually work really well can you recommend any specific ones to help towards par?

Any brands for the T5 ?

I use iquatics I think they are based on ATI but ATI are hard to get for me in the uk. No idea if they are as good.

How long have you had your sps and are they growing? Are they basing out and showing white tips at the ends where it should be growing? If you see growth then the light is sufficient.

If you got them 6 months ago and they look today exactly the same as 6 months ago with no growth at all, then you need to turn the lights up.

The ones at the top are definitely growing. I can’t say if it’s good growth or not though. The one lower down is basing out nice but not really growing upwards much. I’ve had them about 12 months . But even light aside it hasn’t been an optimal growing environment for them.

 

[eggie]

I use iquatics I think they are based on ATI but ATI are hard to get for me in the uk. No idea if they are as good.

Never heard of that brand try getting better bulbs. Cheap T5 bulbs tend to not last long and drop par.