Watts per gallon!??

[Olena]

Hi,
I am growing plants in my tank. Recently I had to replace my fluorescent bulb (it came with the kit) for the f15t8 15 watts 6500K. It is 15 inches from the hood to the gravel. Is it enough light? I read in some sited that watts per gallon is not the correct measurement. If it is then I would need a new fixture and three or more of those bulbs. I am confused.

 

[Mebbid]

I first found the WPG rule when I first started looking at growing plants in my 29g. Following that rule it would have cost me about $400 to get a high powered light in my tank. That rule is complete BS.

What size tank do you have?

That light fixture you have will be good enough for low light level plants such as Anubias, java fern, java moss, and bolbitis.

 

[bshenanagins]

I first found the WPG rule when I first started looking at growing plants in my 29g. Following that rule it would have cost me about $400 to get a high powered light in my tank. That rule is complete BS.

What size tank do you have?

That light fixture you have will be good enough for low light level plants such as Anubias, java fern, java moss, and bolbitis.

My lord where were you looking!? Haha. Anyway the rule is kind of out of date due to the varying options of lighting now: flourescent, metal halide, LED, etc. After some research it seems that the consensus is that the WPG rule really only applies to tanks between 20-55 gallons and anything less or more than that is up in the air. It's a good guideline but it all depends on the type of plants you have, and how close it is to the substrate. I have 130 watts over my 40 gallon and I recently just raised the fixture to even out the spread of light (BBA infestation). Trying to get more plants to outcompete the pesky algae. But yes anubias and javas would do just fine under that light depending on the tank size.

 

[Olena]

Its 20 gal high. So what is the best fixture for midium to high light I should have on it?

 

[Mebbid]

If it were me, I would stick a dual t5ho light fixture on top of that tank although a single one would most likely get you what you wanted. Take a look at the aquatic life dual t5ho fixtures; they are reasonably priced and work very well.

 

[hecurcia]

Dual t5HO will give you high light. If you are not doing co2 + fertilizers, it will be a pain in the neck and algae will take over your tank.I would go with a dual t5 NO and even raise the fixture a little bit.

 

[Mebbid]

Dual t5HO will give you high light. If you are not doing co2 + fertilizers, it will be a pain in the neck and algae will take over your tank.I would go with a dual t5 NO and even raise the fixture a little bit.

I ran a dual t5ho over my 29 which is only 2" taller than a 20g high. Even then my gravel was exceptionally deep so the difference is negligible. Using glut for carbon and dry ferts I had absolutely amazing results and almost no algae.

Any tank with a medium - high light you are going to potentially run into issues with algae, it's a common issue with planted tanks.

 

[hecurcia]

I ran a dual t5ho over my 29 which is only 2" taller than a 20g high. Even then my gravel was exceptionally deep so the difference is negligible. Using glut for carbon and dry ferts I had absolutely amazing results and almost no algae.

Any tank with a medium - high light you are going to potentially run into issues with algae, it's a common issue with planted tanks.

That is what I meant. You have to do ferts and any type of carbon supplement to avoid algae, otherwise it will be a chaos. I have a 20 gallon tall too with the dual aquaticLife T5HO and without ferts and co2 it was just a mess. Here is a pic

 

[Mebbid]

That is what I meant. You have to do ferts and any type of carbon supplement to avoid algae, otherwise it will be a chaos. I have a 20 gallon tall too with the dual aquaticLife T5HO and without ferts and co2 it was just a mess. Here is a pic


View attachment 191928

Looks like a nice tank to me

 

[hecurcia]

Thanks, this is how it looks now. So for the OP, if she/he is planning on doing ferts and co2, a dual t5HO is the way to go. If not so, I would recommend a single T5HO or a dual T5NO. Ferts might still be needed but not in high demand. Also, it depends on what type of plants she/he will be getting.

 

[Olena]

That is what I meant. You have to do ferts and any type of carbon supplement to avoid algae, otherwise it will be a chaos. I have a 20 gallon tall too with the dual aquaticLife T5HO and without ferts and co2 it was just a mess. Here is a pic


View attachment 191928

This is indeed very nice tank! I will be looking for a two lamps fixture one then.
Thank you for your advice!

 

[Matt68005]

Ya you don't want too much light, once algae grows on the plants leaves its pretty much all downhill from there on. Use l.e.d light or else it will grow and kill them.

 

[hecurcia]

A sign of the imbalance between ferts, light and co2 is the appearance of algae. The "trick" to avoid or minimize algae and maximize a healthy planted tank is to find that balance. If your up to the maintenance and responsibility to find that balance, you will be ok. If you go with high light you must go all in, no excuses or shortcuts. Read, research and ask questions. I speak from personal experience. Exactly one year ago, i got the dual T5HO and I though that was all i needed. Wrong. I learned the hard way and I am still learning. In high light planted tanks, you will be always tweaking something, light, ferts and the amount of co2 that is being pumped in. Yet, the changes are not that great that could throw your tank out of course. Always be on the look out for signs that something might be wrong, like algae, large pH swings and the overall plant health.

 

[AquaShark]

For low to medium light you could get a LED light. The smaller sizes are under $100. So depending how big is your tank it wouldnt be too expensive. Finnex ray and Current USA are both highly recommended . In the long run LEDs would be cheaper because of bulb replacement. Sadly I learned that too late. Bulb replacements practically cost enough to buy a new fixture.

EDIT: I didnt see that you said 20 high until after. LEDS wouldnt be too expensive. I had 48 watt T5HO on my 29 gallon and ended up running into serious algae problems.

 

[Mebbid]

For low to medium light you could get a LED light. The smaller sizes are under $100. So depending how big is your tank it wouldnt be too expensive. Finnex ray and Current USA are both highly recommended . In the long run LEDs would be cheaper because of bulb replacement. Sadly I learned that too late. Bulb replacements practically cost enough to buy a new fixture.

I agree about the cost of bulb replacements, but I just don't like LEDs for planted tanks. They seem to cast too many shadows imho and it can detract from the look of the tank.

 

[germanyt]

Watts per gallon is an outdated rule of thumb. I have nearly 4 watts per gallon on my tank but PAR rating is what matters. It's a measure of light intensity and various depths of water. Unfortunately you won't find any lights that use PAR is a rating. Two 96 watt quad T5H0 lights can have very different results. Ballasts, reflectors, bulbs, etc all make a difference.

 

[DanielAG]

I've got a 20 gallon tall with a quad t5ho on it. Technically speaking, in terms of wpg, I'm at 4.8.

Now, had I knew about PAR before my LFS brainwashed me into thinking higher WPG = good...I could have avoided throwing out an entire bed of of HC Cuba because of a BBA outbreak. As it is now, I'm seriously contemplating making the switch to somthing 'less' powerful. I'm also leaning towards the idea that HC requires a certain PAR to grow...but that's a different story.

Lookup LED light compendium on google . There's a forum that has a lot of led fixtures that have links to PAR results too.

Hopefully it works out for you!