# Opinions on MH lighting time?



## magnolia95 (Aug 15, 2005)

Hi all,

I just purchased a 150W MH fixture for a 50G tank (because I couldn't resist that rippling effect...lol!)

Anyway I have read a lot of threads that say to only have them on for around 6-8 hours a day because of their intensity, otherwise all sorts of horrors ensue (algae, pruning every day...) The thing is, I got them because I like watching the light (as well as hopefully being able to grow things I haven't been able to before) So if I have to turn them off after only 6 hours I won't be very happy.  

What is everyone's experience? Should I have got some sort of MH/PC combo? Can I leave them on for the normal 10 hours? And do the PC's in those combo fixtures really do any lighting considering they're 12 inches above the water?

Any words of wisdom or otherwise greatly appreciated.

Maggie


----------



## TNguyen (Mar 20, 2005)

magnolia95 said:


> Hi all,
> 
> I just purchased a 150W MH fixture for a 50G tank (because I couldn't resist that rippling effect...lol!)
> 
> ...


I have seen the Grand Solar I MH/PC combo. The compact on the combo to me is just too high. So I don't really know if it help that much except to give you more time to look at your scape. On my oceanic 75gal, my diy ahsupply compact alone is more intense then the pc on the combo. It is about 3-4inches from the water. I know Luis Navarro take care of 4 setup with only metal halide. I think he mentioned it was on from 9am-5pm. Maybe he can chime in.

http://www.aquaticplantcentral.com/forumapc/showthread.php?t=7984

Thanh


----------



## david lim (Mar 30, 2004)

I have a 250W over a 58g and keep it on 5-9 pm. The plants grow great. The light sits about 1.5 feet away from the water. 
I'm considering DIYing a t5 HO setup when I get more money, but as of right now the light's great. 
As far as algae goes if you keep up with the maintenance (ie water changes, CO2, etc.) I don't believe you'll run into as many algae issues. Enjoy the light! I've had less problems with algae running this setup than previous PCF setups, but I wouldn't conclude that the light's the solution. Many other factors could have existed. 

David


----------



## magnolia95 (Aug 15, 2005)

David,

Do you have any other lighting at all? I just wonder how I'm going to enjoy my tank if the lights are off for most of the time.

By the way my brother's name is David Lim! It's weird seeing it here...

maggie


----------



## david lim (Mar 30, 2004)

Yea, I understand, which is why I say I have my lights on 5-9, or when I'm usually at home . No other light right now.

David

ps ... and yes I'm your brother... heh j/k. i have a little sis named helen lim?!?


----------



## magnolia95 (Aug 15, 2005)

I'm home all day ! I have a niece named Helen Lim...

maggie


----------



## plantbrain (Jan 23, 2004)

Maggie are you involved with SVAS? Well, what about SFBAAPS?
We just had a plant swap (SFBAAPS) and I dropped off some CO2 tanks for dirt cheap to some new members.

You'll do very well to attend a meeting/swap etc, very worthwhile!!! You'll save a lot of time and $$$, that much is definite!!

Ask anyone that is a member.

I'd go 8-9 hours for the light, crank to CO2 only when the light is on.
Low CO2/low nutrients is the main issue for algae.
You just need to match the CO2/Nutrients for the light.

Regards, 
Tom Barr


----------



## david lim (Mar 30, 2004)

magnolia95 said:


> I'm home all day ! I have a niece named Helen Lim...
> 
> maggie


Yea, you might want to run it longer than my 4 hrs. Also I'm using a 250W as opposed to a 150W and it's considerably brighter. Others, including Amano, have had excellent results using a mix of PCF and 150W MH. I believe Amano uses MH 2-3 hrs/ day and the rest of the day is PCF. Tom makes a good suggestion. Excellent people in San Fran, and most of them are friendly, sometimes too friendly .

david

What about Ming? That's my father's name =).


----------



## magnolia95 (Aug 15, 2005)

Tom, 

This is my first real attempt at a planted tank. After a year of just shoving plants in LFS enormous epoxy gravel, with about 1 wpg and no CO2, I finally got serious and have been reading non-stop now for about 4 weeks. So thats why nothing (but java moss and crypts) grew!!!

So I have just purchased a 50G setup, some ADA substrate, and the MH lights. I'm still not ready to plant, got more research to do and CO2 to buy.

I have just emailed to join the SFBAAPS and am waiting for the next event. I was thinking of the SVAS, they have a planted tank group I think?

Thanks for the hints re light. I have also read your EI method and am very interested in trying that. You give good info!

David,

I have read those threads on the staggered lighting and I really like the idea. I'd like to try it but I'd have to return the MH I think to get the PC/MH combo. Kinda got carried away when I bought it without doing full research. Hadn't seen those pretty glitter lines before  
Hmmm so these plant people are real friendly then?  Well that's nice!

No Mings, my father is Lim and my mother is English. 

maggie


----------



## plantbrain (Jan 23, 2004)

M-

All you need to do is get on the mailing list for the group, there is no memebrship fee, just a donation after we save a few hundred $ and is optional.

Go right ahead and do this right.

ADA soil
Tank
Good canister filter
Light
CO2.....................
Lots of plants from day one(SFBAAPS will come in very handy!!)
Mulm from another tank

Dosing is easy, CO2 is not. 

Regards, 
Tom Barr


----------



## gnatster (Mar 6, 2004)

Just another data point for you. 

120 gal tank lit by 2 x 250 HQI 8-10 hrs per day. As long as CO2 and ferts were kept up with there were no problems. Let the CO2 get of whack and bad things happen fast.


----------



## magnolia95 (Aug 15, 2005)

DOsing actually scares me the most. Don't know why just the thought of all those tiny amounts. Mind you I haven't used pressurised CO2 yet.

Filter I thought the 2128 Eheim
I also thought I would get the pH controller because I'm not experienced. In fact this is great if I could just run my understanding of the whole thing by you...

CO2 cylinder to regulator/needle valve/solenoid/bubble counter (Milwaukee have this all in one I think). From here either to a diffuser in the tank (via check valve) or to a reactor outside the tank which has water from tank pumped through it, then back to the tank. I kinda like the first option because there's one less set of equipment to organise (the pump).

I use RO water with Equilibrium and alkaline buffer at the moment. So I find the point at which about 30ppm of CO2 and pH around 6.8 intersect and get my RO up to the appropriate KH.

Is that approximately correct? I really appreciate any correction...

maggie


----------



## magnolia95 (Aug 15, 2005)

Wow thanks gnatser, that's a lotta light, I feel better now. My only real worry was that I wanted to look at the pretty light for more than 6 hours a day without things getting out of hand.  And that I'm a complete novice so I thought the probability of things getting out of hand was quite high....  

Maggie


----------



## plantbrain (Jan 23, 2004)

I think if you come to meeting and talk to folks, you'll feel a lot better and get off to a much better and far less frustrating/less expensive start.

Fish bite, we don't.
I do not suggest the RO thing, you do not need it and we have a number of members in the SJ area.

Extra added work.
Plants need light, CO2 and nutrients.

CO2 is what you will want to focus on.
Test the tap water's GH and KH.
Then adjust to 30ppm using only CO2 to lower it.

I would not suggest using a controller, you can if you want to without issues but if you do not keep an eye on the KH, then things can get out of whack. 

So the control part is not without it's own set of issues.

I would suggest getting a pH meter, like a Pinpoint of Milk, you can accurately see the pH and find the CO2 level based off the KH measurement.

Once you set the CO2 rate at a good levels for plants, the KH is really much less of an issue.

Everyone gets complacent with CO2 measuring and just using the eyes helps a great deal as you get use to using it.



Regards, 
Tom Barr


----------



## magnolia95 (Aug 15, 2005)

Thanks Tom,

I would be real happy to just use my tap water. It's just such a high pH, 8.4, GH 18, KH 14. So I'd have to dilute about 1:2 or 3 with RO anyway wouldn't I? 

MAggie


----------



## summitwynds (Jun 3, 2005)

I have a metal halide 150w combo with 2 65w (Coralife) over a 75 gallon hex, and then over a 44 gallon pentagon shaped tank and a 50 gallon Oceanic show tank I have a 150w metal halide Coralife pendant. I have to say I like the combo unit best as I run that about 11 hours, with only the metal halide on for about 5 hours. The pendants run for about 6 hours on one tank and 8 on the other.

I have pressurized CO2 on all 3 tanks, all with pH controllers, they are all on diffusers with the 75 having an ADA beetle, the other 2 are some sort of generic glass diffuser. I have to say I am happy with the set up. I would be afraid of leaving home without the controllers. 

Im not an expert, just started this "high tech" approach last December and after reading lots of great posts and trial and error, Im enjoying this obsession tremendously.

I sure wish we had a store like Aqua Forest here, I too, love the ADA products.


----------



## e.lark (May 5, 2005)

Hi, I have a 175w MH pendant 8" above a 58g tank. I run the light 12pm to 10pm. Keep a close eye on nutrients and co2 above 30ppm. I havn't had a algae issue yet. I agree, after having MH over a SW tank I had to carry it over to FW planted. I like the ripples and dark shadows.


----------



## magnolia95 (Aug 15, 2005)

Summitwynds,

I am really leaning towards the combo lighting now. I can't afford the ADA combo though. I am interested to know that the glass diffusers work okay. I think I read somewhere else that someone said they waste a lot of CO2. That's not your experience?

Ernest,

Wow your tank doesn't look like a beginners to me. I only hope mine might be half as good. I'm glad to know you have your lights on 10 hours. I still don't know what to do! I just don't want to stick with only MH and then wish I had the combo lighting...

maggie


----------



## e.lark (May 5, 2005)

One thing you may regret.... The discus you saw in the pic of my sig. I had the discus for about a month. IME they don't do well under high lighting and become shy. Mine eventually just stayed hidden and only came out to eat. I have now returned them and went with a school of rasbora hets. 

If you like the ripple keep the MH. You can grow plants with either and you can also have algae issues with either as well.


----------



## summitwynds (Jun 3, 2005)

Maggie,

Like you said, I also love to have the lights on most of the day. I can accomplish this with the Coralife Combo (150W MH and 2 65 watt bulbs). The price was fair too, especially compared to the ADA combo. You can see it (work in progress) in the link below.

I have been very pleased with the glass diffusers, I would highly recommend the ADA one. I have the pollen glass beetle and it sends up a nice fine mist of co2. I havent seen a waste of CO2, On the 75 hex with the ADA diffuser, I have filled the tank once since setting it up in Dec. I have it on a pH Controller, I run an air pump at night and everything seems to be going fine. Not to say I haven't had my share of beginner errors.

You can see the set up on the hex here: 
75 Gallon Set up

I am trying to get my hubby to make a nice pine trim board around the bottom and top of the tank to dress it up. This will eliminate the light glare between the fixture and the tank. We are also going to build a shelf system beside the fireplace where the first set of stairs go up. This will house the wood barrel which the Eheim (sitting behind the stone on the stairs presently) fits into nicely. The ballast to the MH is in the box on the 2nd ledge to the left of the tank. Its been a tough (but fun) tank as everything is seen since the stairs go up behind the tank. I pretty much have to put scuba gear on to work on the tank with it being 30" deep. When I tear it down I hope to put a really thick layer of ADA substrate in to make it a little easier to reach. Anyone ever put ADA substrate on top of existing substrate (gravel & Flourite)?

Amy


----------

