When to change T5’s? Decreasing PAR or increasing algae growth??

[Paleozoic_reefer]

Hello fellow reefers!
I had a fellow reefer (and former LFS owner) come over and was admiring my tank and noticed a larger the normal amount of hair algae in my tank. I chalked up the extra algae growth to the removal of a large amount of chaeto in my sump which slows down as the chaeto takes off again. But, he stated it may be my T5’s are loosing their spectrum. I told him the PAR hasn’t changed since I got them replaced them about 10 months ago. My assumption is that a decrease in PAR would be my sign to change out the bulbs, but he said he used to use algae growth not PAR as his sign to change out his bulbs since the spectrum decreased over time while PAR will remain the same. Who’s right??

 

[bnord]

interested to see if there is a sound basis to the spectrum theory - I change on a quarterly pattern so that each bulb lasts a year - for no good reason except I dont want to blast the tank with 4 fresh bulbs

 

[Paleozoic_reefer]

interested to see if there is a sound basis to the spectrum theory - I change on a quarterly pattern so that each bulb lasts a year - for no good reason except I dont want to blast the tank with 4 fresh bulbs

Agreed! I rotate as well for the same reason. I can see some possible truth to his assumption on decreasing spectrum over time but I don’t know if it would matter enough to actually affect the PAR value…?….

 

[bnord]

Agreed! I rotate as well for the same reason. I can see some possible truth to his assumption on decreasing spectrum over time but I don’t know if it would matter enough to actually affect the PAR value…?….

need someone with more sophisticated sensing equipment than we have to answer the question properly, then I bet not all bulb configurations will age consistently....

 

[Lbrdsoxfan]

interested to see if there is a sound basis to the spectrum theory - I change on a quarterly pattern so that each bulb lasts a year - for no good reason except I dont want to blast the tank with 4 fresh bulbs

Interesting way to do it. I got a few months til I hit the 12 months mark on current bulbs, I may try that one!

 

[F i s h y]

This is a good question but it also depends on the amount of time each day you run your bulbs and if they are being run at the correct temperature. Over heated and over used bulbs will not last as long. There are several factors I think.

 

[bnord]

Interesting way to do it. I got a few months til I hit the 12 months mark on current bulbs, I may try that one!

knowing me as I do, I place a small strip of tape on the edge least visible adjacent to the bulb and write the replacement date on it. That said, I would like to have the data based confidence that a longer "between changes" interval is acceptable...

 

[bnord]

This is a good question but it also depends on the amount of time each day you run your bulbs and if they are being run at the correct temperature. Over heated and over used bulbs will not last as long. There are several factors I think.

perfect! and I I use a hybrid set up, with the T5's as a noon day sun blast, only run them 4 hours - been thinking of a 3 hours mid day and 2 hours later in the afternoon

 

[Paleozoic_reefer]

This is a good question but it also depends on the amount of time each day you run your bulbs and if they are being run at the correct temperature. Over heated and over used bulbs will not last as long. There are several factors I think.

Well, if someone does run their bulbs for a long period of time everyday would you start to degrade the spectrum before you decrease PAR? If you run your bulbs for either short or long periods I would assume the effects of a degraded spectrum would be the same in the end for both lengths of time. I run my T5 for 8 hrs to make sure my mags get enough light so I work them pretty hard, and only change them when I see PAR decreasing. Now I’m wondering if there is an additional metric I should be using to determine spectral degradation ?

 

[F i s h y]

@Dana Riddle can you assist with this?

 

[Potatohead]

Here's the schedule I have settled into over the year. I change two bulbs at a time and usually space them at least a month apart.

Full spectrum and actinic bulbs I change every 11-12 months, they run for 6.5 hours per day
Blue bulbs I change every 14-16 months, 6.5 hours per day
Dusk/dawn blue bulbs every 11-12 months, 9 hours per day

Works for me

 

[Lbrdsoxfan]

knowing me as I do, I place a small strip of tape on the edge least visible adjacent to the bulb and write the replacement date on it. That said, I would like to have the data based confidence that a longer "between changes" interval is acceptable...

Historically I've always dated bulbs with a paint pen. I checked par numbers when I started out, I was going to check par at 12 months to see what the difference is. I am noticing that there needs to be a little more light involved for sand dwelling softies and mushrooms to open up properly.

 

[oreo54]

need someone with more sophisticated sensing equipment than we have to answer the question properly, then I bet not all bulb configurations will age consistently....

BRS did a t5 bulb longetivity test video and posted ATI's "opinion"

How often should I change my T5 bulbs?

To keep corals happy, T5 bulbs need to be replaced regularly. We'll explain the factors that affect bulb life and teach you when and how to replace them.

www.bulkreefsupply.com

This is one but not the only BRS vid on tube life.

When do we REALLY need to change out T5 bulbs? | BRStv Investigates

We are finally putting to rest the age old question of when you need to change out your T5 bulbs. Follow along as we share our testing data where we run T5 bulbs for a simulated 2-yrs, taking PAR and spectrum readings the entire way, to finally decide what happens as T5 bulbs age. The results...

www.bulkreefsupply.com

 

[Paleozoic_reefer]

@oreo54 this is exactly what I was looking for! Looks like the shift is minimal over time and PAR IS the best way to determine when to change the bulbs.
Thanks!!

 

[bnord]

BRS did a t5 bulb longetivity test video and posted ATI's "opinion"

How often should I change my T5 bulbs?

To keep corals happy, T5 bulbs need to be replaced regularly. We'll explain the factors that affect bulb life and teach you when and how to replace them.

www.bulkreefsupply.com

This is one but not the only BRS vid on tube life.

When do we REALLY need to change out T5 bulbs? | BRStv Investigates

We are finally putting to rest the age old question of when you need to change out your T5 bulbs. Follow along as we share our testing data where we run T5 bulbs for a simulated 2-yrs, taking PAR and spectrum readings the entire way, to finally decide what happens as T5 bulbs age. The results...

www.bulkreefsupply.com

thanks Oreo - this is why I love this site

 

[nereefpat]

Differences in algae growth would be anecdotal at best. I haven't noticed a trend there, but I know people do talk about it.

I just change all 6 at once on mine every 12-18 months. Mine runs about 9 hours a day.

Your tank looks great, so do whatever you've been doing.

 

[Paleozoic_reefer]

@nereefpat thanks!!