Cfl Wattage/co2 Question

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kcharley

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Hi all.

I'm aware of the general rule that a CO2 system is needed with 2 or more wpg.

My understanding is that T5 lighting effectively produces more watts than the bulbs claim (although I don't understand why), so that a 20W T5 is effectively somewhere between 30 and 40 watts from a T8.

My question is does a compact flourescent bulb wattage need some adjustment (similar to T5) to compute wpg?

In my specific instance, I have a 22 gal aquarium with an old T8 strip light converted with a 36W compact flourescent light and reflector.

In other words, am I really at 1.6 wpg or something higher?

The practical concern is whether I have to go to a CO2 system (although I anticipate getting one anyway once I better understand the overall macro and micro- nutrients necessary to grow plants and reduce algae growth.)

In case it makes a difference, the plants currently in the aquarium are 5 stalks of hornwort, 4 long (> 24") stalks of anachris, a balansae crypt, an amazon sword, two java ferns and some water sprite. I am dosing weekly with Seachem Flourish.

Thank you in advance for any guidance.
 
It is correct that over 2WPG of T12 you need CO2. This can basically be applied to T8 or T10 too as they aren't too far apart in terms of efficiency

T5 doesn't effectively produce more watts than the bulbs claim. In a way it is exactly the opposite. What we are talking about is efficiencies and restrike issues (where light reflects off your reflector and hits the tube on the way past so in essence is lost)

Therefore 1W of T12 = 1W of T5HO. The difference is how much of that 1W goes towards the tank which means that efficiency wise the T5 gives more usable wattage than the T12. The WPG rule always assumes that reflectors ARE already in use. If you don't have GOOD reflectors you are already losing quite a lot of the light from the tube anyway.

Think more that a 20W T5 is maybe giving you 17W of light in the tank whereas a T8/T12 may be giving you 10W. They cannot give more watts than they are producing. When we say T5HO is up to 2x a T8 we mean that is up to 2 x more efficient in the light that is actually being directed toward the tank and penetrating to the bottom.

CF does need some adjustment but I would suggest closer to 1.5x as although they seem very popular, good reflectors are very hard to find for PC and there are lots of restrike issues with reflectors due to the close proximity of the '2' tubes

What we have to do because the WPG rule is so firmly fixed in the minds of this hobby is assume say: If T12 = 1 then T5HO = 2, whereas what it should really be is 1 = total wattage available and then tubes would be something like T12 = 0.5, T5HO = 0.9 etc.

I think you should be able to get away with DIY CO2 with 36W PC over 22USG but it is borderline IMO although of course I would suggest to all (even those on low WPG) to go pressurised.

Macros and micros are easy. Macros are NPK (nitrogen, phosphate and Potassium), micros are trace elements, mainly metals, that all living things need a teeny bit of to flourish. Think of your Mum telling you to eat your greens as they are full of Iron. She wasn't using Iron as a similie.

Flourish is only a source of micros. You need to add some macros as well.

AC
 
It is correct that over 2WPG of T12 you need CO2. This can basically be applied to T8 or T10 too as they aren't too far apart in terms of efficiency

T5 doesn't effectively produce more watts than the bulbs claim. In a way it is exactly the opposite. What we are talking about is efficiencies and restrike issues (where light reflects off your reflector and hits the tube on the way past so in essence is lost)

Therefore 1W of T12 = 1W of T5HO. The difference is how much of that 1W goes towards the tank which means that efficiency wise the T5 gives more usable wattage than the T12. The WPG rule always assumes that reflectors ARE already in use. If you don't have GOOD reflectors you are already losing quite a lot of the light from the tube anyway.

Think more that a 20W T5 is maybe giving you 17W of light in the tank whereas a T8/T12 may be giving you 10W. They cannot give more watts than they are producing. When we say T5HO is up to 2x a T8 we mean that is up to 2 x more efficient in the light that is actually being directed toward the tank and penetrating to the bottom.

CF does need some adjustment but I would suggest closer to 1.5x as although they seem very popular, good reflectors are very hard to find for PC and there are lots of restrike issues with reflectors due to the close proximity of the '2' tubes

What we have to do because the WPG rule is so firmly fixed in the minds of this hobby is assume say: If T12 = 1 then T5HO = 2, whereas what it should really be is 1 = total wattage available and then tubes would be something like T12 = 0.5, T5HO = 0.9 etc.

I think you should be able to get away with DIY CO2 with 36W PC over 22USG but it is borderline IMO although of course I would suggest to all (even those on low WPG) to go pressurised.

Macros and micros are easy. Macros are NPK (nitrogen, phosphate and Potassium), micros are trace elements, mainly metals, that all living things need a teeny bit of to flourish. Think of your Mum telling you to eat your greens as they are full of Iron. She wasn't using Iron as a similie.

Flourish is only a source of micros. You need to add some macros as well.

AC

Thanks AC.

That is a great explanation of the difference between various lights. You made it very clear that what matters is how much light goes into the water. Thus, the quality of the reflector, the size of the bulb and the placement of the bulb in relation to the reflector has a big impact on efficiency/how much light goes into the aquarium.

That said, I upgraded the old strip with http://ahsupply.com/mcart/index.cgi?code=3&cat=6 (Sorry, I'm a bit of a dinosaur and not very good at links). This is the site recommended in George's pinned item on basic lighting. In other words, I think I have a pretty good reflector with a decently positioned bulb.

You have confirmed my suspicion that I need CO2. I want low maintenance so I will probably spend the extra dollars and go pressurized.

Thank you very much for your posts replying to Jaymz regarding the macronutrients and CO2 sources. Those posts and Aaron's clueing me in that I have nutrient problem are a big help to me.

Regarding the macronutrients, which do you feel would be better, adding a quality substrate or fertilizer dosing. I'm leaning towards dosing, at least initially, as it would be a pain to pull everything out to add a substrate.

Regarding the CO2, am I correct that I should replace my hob with a canister to reduce the surface agitation? (The hob is rated at 200 gal/hour so there is pretty good surface flow.) I suppose I could see how the CO2 levels do with the hob but doesn't this affect my choice of a diffuser vs reactor?

Thanks again for the help.
 
I would start from scratch. Out with the plants and into a bucket, out with the fish and into a blanket wrapped container.

Give the tank a good clean, nutrient rich substrate in and then layer of gravel/sand.

Hardscape back in, Plants back in, Fill her up and then get it up to temperature. Then reacclimitise the fish.

If you are going to start dosing, adding CO2, getting a new filter etc, then why not make sure everything is perfect from the start.

That Hob filter will be far too underpowered for a planted tank. You want something much closer to 800/900lph so yes I would go for a cannister.

Seeing all the above I think you might agree that it would be better to carry on as you are, wait until you get everything you need to start your new project and then only once everything is there start the change.

Believe me it will be one full day of frustration. Through the day you will wish you had never started. When its over you will want to go to bed.

The next morning you will be absolutely glued to the tank and in awe of your effort ;)

AC
 
I would start from scratch. Out with the plants and into a bucket, out with the fish and into a blanket wrapped container.

Give the tank a good clean, nutrient rich substrate in and then layer of gravel/sand.

Hardscape back in, Plants back in, Fill her up and then get it up to temperature. Then reacclimitise the fish.

If you are going to start dosing, adding CO2, getting a new filter etc, then why not make sure everything is perfect from the start.

That Hob filter will be far too underpowered for a planted tank. You want something much closer to 800/900lph so yes I would go for a cannister.

Seeing all the above I think you might agree that it would be better to carry on as you are, wait until you get everything you need to start your new project and then only once everything is there start the change.

Believe me it will be one full day of frustration. Through the day you will wish you had never started. When its over you will want to go to bed.

The next morning you will be absolutely glued to the tank and in awe of your effort ;)

AC

Thanks AC,

I was looking at some Eco-Complete last night. It seems it has phosphate but I didn't see potassium or nitrogen on the list. Am I correct that I will have to do some amendments to get these? Or do the planted aquarists just add fertilizer periodically? I did see some Seachem NPK tablets.

Except for the a growing algae problem, the tank looks pretty good right now (at least for a newb like me). Tonight's water change/cleaning will take care of the algae for the short term. Over the next couple of weeks I'll be gathering/assembly the parts for adding the substrate and CO2.

My wife and I are enjoying it and the fish love going in and out of the plants.

Thanks again.

Greg
 

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