MH vs. CF

[vmahaffe]

vh:

IMHO forget the literature.

I have a virtually identical situation with a 110G tank.
I had 260W of CF - three 10000K bulbs and one 7100K bulb
I now have 260W of CF - two 10000K bulbs and two 7100K bulbs
and 300W of MH - two 14000K bulbs

The 4 hours is IMHO an internet myth which is principally read and subsequently propagated by folks who have no experience or have not experimented with all options.

I run my configuration 10 to 12 hours per day.


Three Items to Note:

• [1] I believe that the comparison of MH watts and CF watts is invalid as
  • [A] the phosphor in CF bulbs produces gaps in the energy spectrum emitted and as such the MH provides a better quality of light; and
  • some energy in CF bulbs is usurped due to fluorescing the phosphor

• [2] At 5WPG nice plants can be grown without CO2 injection. The problem is that too little fertilization inhibits plant growth and and too much fertilization yields excess nutrients both of which generate algae. The appropriate concentration of the various ferts as well as their dosage rate takes some experimenting in order to preclude algae production.

• [3] Should you decide to "blast" your plants please do so slowly (I slobbered up here). Ten hours of MH light the first day and the continuance thereof will melt vals and cause other plants to suffer although they will recover. If I get into this MH introduction again I will start with two hours the first day and increase the MH lighting duration an hour per day thereafter.

TR

BTW: I believe (this belief is very qualitative but is based on experimentation) that minor CO2 injection, such as that produced by DIY two liter soda pop bottle, significantly increases the range of fertilizer concentrations and dosages which generate plant health and growth but which does not generate algae.

Ok, so I should run my CF's for 10-12 hr/day and use my MH for 2 hr/day and slowly build them (over 10-12 days) up to the same timing as the CF's and run both for 10-12 hr/day? Would it be alright to run the lights using the way midiamin stated? That seems to make sense having my MH's on during the part of the day the "sun" would be highest. I have been using 4 96w 12000k's for about a year without CO2 and only using Flourish once a week and have been doing alright. I was only doing monthly watre changes too. I just started doing 10-20% weekly and adding Flourish 2x week and it seems to help, so I am hoping the new lights will make things take off. I will be adding a pressuried CO2 system next week.

 

[midiamin]

Believe it or not, the 4 x 96 watts should be more than enough. Save the MH's for emergencies or a rainy day. You really want to see a change, do more water changes twice a month). The plants will love it (only a suggestion).

 

[jones57742]

Ok, so I should run my CF's for 10-12 hr/day and use my MH for 2 hr/day and slowly build them (over 10-12 days) up to the same timing as the CF's and run both for 10-12 hr/day?

This works for me but please note my comments concerning a narrow range of fert concentration and dosage which will not generate algae.

Would it be alright to run the lights using the way midiamin stated? That seems to make sense having my MH's on during the part of the day the "sun" would be highest.

No reason that it should not.
I just believe that the 10 to 12 will produce greater plant growth but I have no empirical evidence upon which to base this belief.

I just started doing 10-20% weekly and adding Flourish 2x week and it seems to help, so I am hoping the new lights will make things take off.

As mm indicated in the post above typical WC's are 25% weekly (I do 10% daily with RO/DI).

I will be adding a pressuried CO2 system next week.

Partner, IMHO, you better be getting into dry fert's unless you are in possession of independent wealth and can afford the products set forth in the standard Seachem dosing chart or enjoy green water and walls (ie. excess carbon will induce algae production)
Also please note that at higher concentrations CO2 is toxic/lethal to fish.

TR

 

[vmahaffe]

My Flourish bottle says to add 60 mL/60gallons 2x week. I have a 2 L bottle that I paid $25 for, so that should last about 6 months. What advantage do dry ferts have over that?
I thought CO2 deterred algae growth? I plan on running about 25-30ppm. I have a nice pH meter I got free to make sure my pH doesn't drop below 7.0. My water right now is above 9.0.

 

[jones57742]

Flourish ... What advantage do dry ferts have over that?

Short form is that Flourish is basically micronutrients.
Please refer to the link which I included in my previous post for the long form answer to this question.
Have you reviewed the Seachem dosing chart which I referenced in my previous post?

I thought CO2 deterred algae growth?

When supplied with the appropriate concentration of macronutrients* CO2 does deter algae growth by health and growth of the plants as plants are more efficient consumers of nutrients than algae. (* a poor example is that you are on the Moon and your survival kit contains sufficient oxygen for 60 days but no water is in your kit).

I plan on running about 25-30ppm. I have a nice pH meter I got free to make sure my pH doesn't drop below 7.0. My water right now is above 9.0.

You may want to review the Kh, Ph, CO2 correlation chart.
Please note that higher concentrations beyond the recommended range may be toxic or lethal to fish.

TR