108 watts on 29gallon?

**sweeneyc** · 01-07-2013, 01:15 AM

I have 108 watts on a 29gallon. They are both 6.7 watts. Is that too much? I mean to keep swords, cabomba, hemianthus baby tears, and possibly some rotalas.

My water is green, pea soup green. I think it is because I had 10,000K bulb on there for the majority of the time, which gives off a lot of blue light. Will the removal the bulb make the problem better?

**Cliff** · 01-07-2013, 01:26 AM

You are at high level of light, even with 6700K bulbs. But I would certainly recommend switching to 6700K bulbs

Are you using ferts or CO2 in this set-up as well ?

**biotsrama** · 01-07-2013, 02:02 AM

Agreed with Cliff--with that amount of light (assuming it's compact fluorescent), additional fertilizers and carbon sources will likely be needed, or algae will take over.

**sweeneyc** · 01-07-2013, 02:26 PM

I haven't used any ferts yet, except for once last week I dosed with a plant supplement from API.

Right now, I have two smaller swords in there and a few bunches of cabomba, separated. Should I start dosing with that API again, weekly? My water is green green. I can't get it to go away.

**sweeneyc** · 01-07-2013, 02:27 PM

also they are not necessarily compact fluorescent. they are T5s.

**biotsrama** · 01-07-2013, 02:49 PM

Originally Posted by sweeneyc

Right now, I have two smaller swords in there and a few bunches of cabomba

I think before you start dosing fertilizers, I suggest having more plants in the tank. Otherwise, all the nutrients will just feed the algae.

In the meantime, limiting how much time the light is on per day will help with the green water somewhat. (How many hours/day is it on usually?)

There are more intensive solutions--like getting daphnia or a UV sterilizer. But I would first try getting more plants, of the relatively undemanding, fast-growing type, and cutting back the light, and see if that fixes the problem.

**Taurus** · 01-07-2013, 04:16 PM

This is why I aksed in sweeneyc's other thread on the subject just how many hours per day the lights are on. I also suggested a black out of tank lights for for a few days with several big water changes during the black out period.

sweeneyc is going to need to limit the amount of time the lights are on until he does plant some plants in the tank.

High lighting will require high light plants, co2, ect.

Originally Posted by biotsrama

In the meantime, limiting how much time the light is on per day will help with the green water somewhat. (How many hours/day is it on usually?)

**Cermet** · 01-07-2013, 05:20 PM

Really, 6.7 watts per gal AND 10,000 K? Your real goal is to grow algae to feed brine shrimp, correct? Kidding ...

In my opinion, you will never succeed in defeating the algae issue with that amount of light intensity and the wrong color temperature. Keeping the lights on for less time will slow algae growth but since you have the wrong color temp, the plants will do very badly rersulting in you defeating part of what you are trying to do - grow have healthy plants.

You need to get the correct color lights and lower the intensity down to 2/3 watts per gallon. Even then, at some point, you will very likely need to add some trace nutrients (like Fe and K) for the plants.

And +1 to Taurus

**sweeneyc** · 01-08-2013, 12:12 PM

I've replaced the one 10,000k with another 6.7. I'm currently blacking out my tank and I will be adding more planta today. Should I remove one of the bulbs? It would drop me down to one 54 watt 6.7. I know you said 2-3 w/gal and 54 isn't quite enough but should still work, right?

**Cermet** · 01-08-2013, 12:22 PM

You don't want a tank filled with algae; getting correct temperature tubes (6700 K like you said) gives the ideal 'light spectrum' for the plants. In this way, the plants can get far less total wattage of wasted band width yet you will be giving the plants far more energy where they need it (red and lesser blue); net result will be that the plants will grow far btter with the lower wattage (one tube) and algae will be stressed (due to lack of extra energy all over the spectrum - especially the blue - and that the plants use up most the nutrients like nitrates.) This will help the algae issue not to come back. Do consider, with moderate lighting to use ferts from time to time to provide Fe, K, Mg, S; Ca should be in the water unless very soft and phosphates are huge if you have fish.

If the plants do poorly, consider both tubes but try one and see if the plants do well. Be sure to provide a full eight hours but avoid needing more than that.

That all said, after checking the firat post, I find that 108 watts in 29 gal is 3.7 watts per gal; where did you get 6/7 watts per gal? In other words, two tubes (correct color temp) will be the very high end of the range but maybe doable if you use ferts carefully (don't over dose! and use tabs only for plants that can use them.)