tonym

i use split photo period it helps but the best way is to have fast growing plants to out compete algae ( ps also good for compost heap)

MatPat

I have read through this thread again and it does seem that reducing the lighting period (a "noon burst" may also be considered a light reduction depending on the application) may be the best effort to reducing algae. A lot of folks with high light tanks (myself included), seem to have some issues with algae in their tanks.

I think the majority of issues are CO2 related since fertilizing has been covered pretty much by the EI and PPS methods so fertilizer deficiencies should not be much an issue any longer. Some folks just just can't seem to get enough CO2 into their tanks regardless of their methods and reducing the light intensity/duration will help with CO2 levels.

I have combatted both Green Dust and Diatoms successfully by reducing my photoperiod and intensity of lights. I think the one things we may have overlooked (or not mentioned) thus far in this discussion is determining and or applying the Watts Per Gallon rule.

Wasn't the WPG rule created a long time ago when T-12 lamps were our only source of lighting for planted tanks other than incandescent bulbs? T-8 lights have now replaced T-12 lamps in most commercial strip light fixtures today. T-8 lamps give us more intensity per watt when compared to T-12 lamps. How much do we decrease the original wpg rule for the greater intensity of T-8 lamps?

Compact Flourescent lights are a big step up from the T-8 lamps in intensity per watt yet people still use 3+ watts per gallon with these more intense sources of light. Do we need to decrease the WPG rule more to take this more intense light source into consideration? How much more intense are PC lamps..are they double the intensity of T-12 lamps?

I believe the linear T-5 lamps are an even greater increase in intensity over the compact flourescent lamps since they have less restrike and possibly even better reflectors. Should the WPG rule be decreased even more for linear T-5 lamps and if so, by how much?

One of the SWOAPE members, rwoehr, is growing a nice variety of plants in his 75g tank with 108 watts of T-5 lights. I don't think I would try to grow those plants with 120w of T-12 lighting over a 75g tank

I realize the WPG rule was originally devised to make it easier on new hobbyists to select lighting for their tanks but again, it was created with the inefficient (by today's standards anyway) T-12 lamps.

We used to believe PO4 caused algae and a lot of folks now keep their tanks at 2ppm or better. It is now commonly believed that increasing PO4 levels actually reduces Green Spot algae. I really think when dealing with lighting and the WPG rule we need to revise it for todays higher intensity more efficient lamps. The fertilization methods have changed greatly since the WPG rule was developed why not revisit the WPG rule also?

ruki

This is really complicated. Lots of different types of algae out there. Lots of different water conditions and plants. My guess is that bright light with plants that can take advantage of it will help control algae. Do this with plants that can't fully take advantage of this and algae may gain the upper hand.

This is my personal crusade on this forum.
Repeat after me, three times: "WPG is an estimate, not a rule."

My rough calculation is that WPG is +/- 50 percent considering tube technology (efficiency), tube spectrum, and reflector.

My 2nd personal crusade on this forum is that Compact fluorescent lights only make sense for tanks less than 24 inches wide. Linear tubes, whether T8, T5, or T5 HO make much more sense for tanks wider the 24 inches wide. This is due to three factors.

Factor one is that power compact tubes are bent in a way that sends light back into the tube. This means that reflectors are basically crippled with these lights.

Factor two is that the ends of fuorescent tubes don't produce as much light, so really short tubes don't produce as much light. So this technology is appropriate where you would have to use a really short tube because of limitation of physical space.

Factor three is that aquariums tend to be rectangular. Therefore, it seems totally insane to me to have 48 inch compact flourescent fixtures when T5 HO produces a little bit more light per watt than compact flourcent lamps and can have much better reflectors. T5 HO also work better warm and don't need (the wasted energy for) a fan when the fixture is designed properly.

Yes, there are some tables online for this. You will probably like this http://woo.gotdns.com/Aquarium/CalcL...h=18&Length=48

What makes more sense to me is to come up with a scheme to modify lumen/lux watt meters. Need to fliter out the UV and infared to get something close to PAR, then notch out the green. $100 for the light meter, $100 for the filter is my gut guess. May only make sense for photographers who have other uses for the filters and meter.

In order of efficiency of lumens/watt:
T5
T8
T5 HO
Power Compact *
T10
T12
T12 VHO
* I have a spiral twist hydrobulb that claims to be better than metal halide, but provides no proof for this on the bulb package

Repeat after me...

With the greatest respect, but can't help being fanatical when people want to use rough estimates as absolute rules.

rhinoman

I tried dosing, I tried presurized CO2. I didn't see much of a change in algae growth. I cut back my lighting period from 10hrs/day to 8hrs/day my algae growth slowed noticibly. My 2500G tank will be low tech with 4x 1000w MHs. I will start with 4 hrs per light per day. I'll run 4x 96w CF's about 8 hrs/day. 2 13w CF's will run 12hrs/day. 10 lunar lights will run when the 13w's turn off.

standoyo

Is it true T5's have a lower life span than T8's?
Somehing about less gas.

Laith

This is the first time I've heard this. T5s, as far as I know, have a *longer* usable lifespan than T8s...

So far I've been running T5s on planted tanks for just about two years without changing them and still have yet to see a problem.

Edward

rhinoman

The 2500 will be built when the house is built fall "08".

gf225

What is the difference between T5 and HO T5, and why is "non-HO" T5 more efficient? I thought HO T5 i.e. linear 5/8" dia. 24w, 39w, 54w, 80w were the most efficient...

A_Shea

i have 2wpg on my 55. two 55 watt 6700k pc, and have been able to grow anything i have wanted. Glosso and hc have all done great, wonderful carpets of each.