# Managing T5-Ho lighting



## K Randall (Nov 23, 2004)

I bought a new 4 bulb T5-HO fixture for my new 75G tank, and it seems a LOT brighter than my 4 (admittedly not new) 55W CF's on my old 75G. I was running the 4 55W CF'S 10 hours per day on the old tank, but I'm afraid of causing algae problems with this fixture with the same photoperiod. 

So for now, until I hear from some of you that have used these, I'm running just two lamps for 8 hours per day. (4 hours in the AM, four hours off, and 4 hours on again in the PM, just for viewing's sake). I am used to running relaively high light systems, and the tank has plenty of CO2. I can dose nutrients as needed... That's not. Problem either.

One thing I DO have to work through carefully is that my tap water is high in phosphate. (3ppm). In the long run, this isn't a bad thing, it just gives the plants a nice boost when I do water changes, and they slurp it right up. But when I set up a NEW tank, I have to be careful to give the plants enough light for growth, while at the same time, not causing algae problems with too much light until the plants have knocked back the PO4 level. There should be plenty of available nitrogen in the substrate, because the bottom half of the substrate is Amazonia.

Any help with managing these lights?


----------



## niko (Jan 28, 2004)

That experience brings you to the moment when you understand why for years I've been calling compact fluorescents "an obsolete technology". The reduction in wattage needed is easily 50% if the T5HO use individual reflectors.

New issue with the T5 you may have - if they use individual reflectors the light beam is narrower than the old CFs.

I would run the new T5s only for 4 hours in the middle of the day to start with. Don't know about viewing pleasure in the evening. Better careful than battling algae.


----------



## K Randall (Nov 23, 2004)

These are all in one reflector. They are also sitting up several inches above the water surface. (brackets on the edge of the tank)

If they are so bright that you can only run them for 4 hours, IMO, they are pretty useless! Hope you're wrong!


----------



## Yo-han (Oct 15, 2010)

I probably don't have to tell you to just make sure your plants have every nutrient they need with that amount of light. PO4 is available, NO3 as well (be careful, with high PO4 in the water column it is better to have high NO3 in the water column as well to prevent cyano), a little more micro than you're used to and last but definitely the most important, lots and lots of CO2. 

I can manage 6x54W T5HO with individual reflectors over my 100G but in the busy weeks where I forget some dosing, algae take over quick. I'm only running full light 7 hours a day. Maybe a nice way to start is 8 hours with two bulbs and after 4-6 weeks start adding the other 2 in the middle of the day for 1 hour and every week an hour more.


----------



## Michael (Jul 20, 2010)

One of our members in DFW APC reports good results with just one T5 HO tube above a standard 55 gallon tank. This is a CO2 and EI aquarium.


----------



## K Randall (Nov 23, 2004)

Yo-han said:


> I probably don't have to tell you to just make sure your plants have every nutrient they need with that amount of light. PO4 is available, NO3 as well (be careful, with high PO4 in the water column it is better to have high NO3 in the water column as well to prevent cyano), a little more micro than you're used to and last but definitely the most important, lots and lots of CO2.
> 
> I can manage 6x54W T5HO with individual reflectors over my 100G but in the busy weeks where I forget some dosing, algae take over quick. I'm only running full light 7 hours a day. Maybe a nice way to start is 8 hours with two bulbs and after 4-6 weeks start adding the other 2 in the middle of the day for 1 hour and every week an hour more.


Thanks, Yo-han. I bought the 4 lamp light, knowing I might not want to run more than 2 most of the time. But it makes it MUCH easier for taking photos, rather than having to jury-rig all kinds of stuff over the top of the tank. I've set it up with the two banks of lights on separate timers, so I can run them when I want them. I also know that they are EXTRA bright right now, because they are still in the burn-in phase, and that won't last long. Your suggestion of how to increase the lighting is pretty much what I was planning. I wish I had a PAR meter available, but my camera's light meter tells me there is lots more light here! (Oh, good! I'll be able to stop fish at a much lower ISO!) 

I am pretty used to managing the PO4 situation with new tanks, since this is a long-standing situation with our town water. In nano tanks, I start them out with bottled water, then start doing water changes with tap water, and the plants catch up quickly. That's just not possible with a 75G tank. I'd KILL myself carrying 75G of bottled water home!<g>

My experience with Amazonia (at least the batch I have on hand) is that it leaches a LOT of nitrogen into the water column, which is why I now cap it with something.(Flourite in this case) That doesn't STOP it from getting into the water column, but it sure slows things down! The one time I used (this) batch of Amazonia without capping it, I was POURING Fleet Enema into the tank daily to try to balance the the nitrate, on top of doing 90% water changes every other day.


----------



## K Randall (Nov 23, 2004)

Michael said:


> One of our members in DFW APC reports good results with just one T5 HO tube above a standard 55 gallon tank. This is a CO2 and EI aquarium.


Wow! Then two over the 75G should be about right for most of the time. Good info. Thanks!


----------



## fishyjoe24 (May 18, 2010)

if each one had it's own reflector I would say that is enough light for a reef, I bet you have high light. just a 2 bulb t5 ho with each bulb having it's own reflectors give high light. it's easier to have lower light, and good c02 then to much light and not enough c02.


----------



## K Randall (Nov 23, 2004)

Thanks, Joey. There is plenty of CO2 available. I have had a lot of experience managing planted tanks, just not these particular lights. And, no, they do not have their own reflectors, so they are definitely not running as efficiently as they could be.

The tank has been set up for a week and a half now. I've been running two of the bulbs 8 hours per day, and allowing the CO2 to get a head-start on the lighting by an hour. No algae at this point, so I don't think I'm over-doing it. I did have to add some traces yesterday.


----------



## Flear (Sep 29, 2012)

as i read this, ... there is also "appears brighter to us" vs "appears brighter to the plants"

when i was looking, i couldn't find a single fluorescent bulb of any time that didn't have a huge green spike (our eyes are very sensitive to green, it appears very bright to us)

otherwise, you only need enough lights for your plants to thrive, if your plants are happy with 4 hours, good-to-go, if your plants are starting to get miserable with 4 hours, ... go for more light.


----------



## K Randall (Nov 23, 2004)

Flear said:


> as i read this, ... there is also "appears brighter to us" vs "appears brighter to the plants"
> 
> when i was looking, i couldn't find a single fluorescent bulb of any time that didn't have a huge green spike (our eyes are very sensitive to green, it appears very bright to us)
> 
> otherwise, you only need enough lights for your plants to thrive, if your plants are happy with 4 hours, good-to-go, if your plants are starting to get miserable with 4 hours, ... go for more light.


I understand that appearance doesn't tell all (or even nearly all) when assessing a lighting arrangement. I don't happen to have access to a par meter, though I wish I did. I have used tri-phosphor bulbs since they first became available, so whatever bulbs I've used have always had a green spike. But it is important that our tanks appear attractive to our eyes too... otherwise, why have them? That's why few people were very happy with the old "Gro-lux" type bulbs used alone, though we often used them WITH a "cool white" bulb of some sort. I don't see any reason NOT to have a green spike in a fluorescent bulb. I want to ENJOY my tanks. 

As far as 4 hours are concerned, few plants that I know of can grow well with that short a photo period... and again, since most of us want to enjoy our tanks, why would we want to be able to see them for that short a period?


----------



## AaronT (Apr 26, 2004)

The T5s are definitely brighter, even without individual reflectors. 

I like hanging my lights so I can simply adjust them higher to adjust light intensity. 

I think most people running T5 lights run them for 8-10 hours with only half of the bulbs on the whole time and a midday burst of light were all bulbs are on for 3-5 hours in the middle. This is how Amano uses his MH / CF combo lights as well. The MH lights are only on 5 hours.


----------



## K Randall (Nov 23, 2004)

Hi Aaron, That's about what I'm planning, once the substrate isn't so "hot". It's the old type of Amazonia, and even though I capped it with a deep layer of Flourite "dark", it's leaching a TON of ammonia into the water column. Even with huge water changes every couple of days, I'm having a hard time keeping the nitrate level down below 30ppm, with another 10ppm or so of nitrite. I'm having to pump phosphate (and traces) into the tank to keep growth looking normal, and I'm afraid of too much light with that amount of nutrients in the water column.

So for now, I'm running just two of the lights 4 hours in the morning 4 hours off, then another 4 hours in the evening. I'm just leaving the CO2 running full time at this point... There are no animals in the tank yet anyway, and I want PLENTY of CO2 available as soon as the plants start to photosynthesize. I'll add more light if the plants look like they need it, over time.

I'd love to hang the light, but the tank is in a sitting area, where the light would be uncomfortable in people's eyes. (I had that problem with MH's over my old 125G, which caused me to eventually switch to a closed top with CF's) also, the room has a vaulted ceiling, so hanging the lights would be difficult.


----------

