new set-up questions - metal halides, wet/dry, live rock

[Howdy]

I picked up a used aquarium and am working on setting this up for a saltwater reef aquarium. That is what the previous owner had used it for as well.

I’ve been searching the forums for as much information as I can find and still have a few questions that I’m unclear on.

1. This is a 72x18x20 tank (120 or 125), currently the canopy is set-up with metal halides and (2) fluorescent fixtures (I’m guessing these are 40 W or so). The metal halides are one on each end and one in the center. The ones on each end have bulbs and are 250W. The ballast is well labeled on these as well. The center one does not have a bulb and is labeled on the ballast as 165 W (MH). Is there such a thing as a 165W metal halide? Do I need this center light even with 500W, plus the standard fluorescents? Depending on the true wattage of the fluorescents, this should give me roughly 580W, and over 4.5 WPG. The main concern I see is that the metal halides are on each end, so the center of the tank may not get what it needs for light (I could space the corals so they are towards the ends I suppose??)..

2. It has a fairly large wet/dry filter with skimmer that currently is full of bio balls. I know many prefer sumps, but I figure I’ll start out with this anyway until I get some experience. I was planning on replacing the bio balls with small pieces of live rock as I read on this forum. Is this a good idea? Do I need to add a light fixture to the wet/dry compartment then for the live rock to stay “alive”?

3. The pet shop here wants $10 a pound for live rock. Is it a good idea just to bite the bullet and get live rock locally so you don’t lose life with the shipping / curing process? Or should I order from some place like live aquaria for much cheaper. Would 90 pounds be enough to get started for live rock? Maybe add some base rock to that??

Thanks in advance,
Howdy

 

[tecwzrd]

If it’s 23 3/8” high it’s a 125 gal. Sounds more like a 100 gal though. I’ve never heard of 165w MH bulb. Are you sure it’s not 175W? Lighting just the end ones would be ok but the MH light only covers about 2 feet and the middle would not be a sufficient place for corals so I would see what you can do about lighting the middle. You may have to replace the ballast if a 150w bulb will not work.

Do you know if the florescent bulbs are PC or VHO? Are the MH Mogul Base "Single-Ended" or HQI "Double-Ended"? I would get the exact specifications on all the lights if possible so you know not only total wattage but also for replacements.

Speaking of replacements if the lights are older then 9 months then you are going to have to replace them which will probably run you $300-$500 depending on the brand/type of bulbs that need to be replaced. If you don’t you will have algae issues.

The bio-balls will likely keep your no3 high and is best to be replaced by lr rubble. Getting base rock ie: www.hirocks.com, lace rock, ect… will save greatly on cost. I’d aim for at least 30%-40% of live rock and getting it from your lfs is ok if you are happy with the appearance/life that is present. Ordering live rock online from liveaquaria.com would probably be better even with shipping costs. See this post & this post for examples.

You really want closer to 130+ lbs of base/lr for biological filtration along with 1500+ gph of water movement in the tank. If you can afford it stocking your tank up to 200 lbs of base/lr would be more optimal.

 

[Howdy]

thanks for the information. I'll need to get more information on the lights when I get home. The single ballast is labeled as 165 W, but I'm not sure that is right (this is a home-made label it appears). It looks the same as the double 250 ballast, except about 1/2 the size. I should be able to find out more on these, I haven't got that far yet ..

What is the reasoning for replacing the bulbs if they are working? I was thinking I'd use them for now until I need to replace them. Also, in reference to this, my father-in-law is an electrician and he said those bulbs run him around $40 each (max). I'm not sure if those are the same though??? what is special about the MH for aquariums? temp? MH 250 Watt are very common I guess for street lights.

The MH bulbs that I have are single ended.

I'll measure the tank as well, it is an All-glass tank.. I think it must be the 125 (72x18x22), but I'll verify. I'm not sure on the height. It was next to a 125 and looked the same and that is what they sold it to me as.



Added 1:10 p.m. CST

This is close to what the bulbs look like. I'll get more detailed information when I get home.

Can I order the MH bulb from one of these discount bulb stores? This is 4000 K which probably isn't right. What do I want for coral, 10,000 K? Anything else that I'm missing that may be different. Rather than paying $80 from one of the LSF's or online shops.

http://www.accessdiscounts.us/sku-26081.html

 

[tecwzrd]

The life of PC/MH/VHO bulbs can last as long as two years. The reason you want to replace them before they die is because typically with a single ended discharge lamp (Mogul Base) you can expect to see between 0.5 K and 1K drop in Color Temperature per hour of operation over the life of the lamp. This color shift which is invisible to the naked eye starts to favor algae and will slowly take over your tank until you change the bulbs.

The $40 MH “street” bulb is around 4K-5K (kelvins) and would be very yellow and not the right “color” for corals. MH bulbs for aquariums usually range from 10K-20K and are supplemented with 03 PC/VHO bulbs for the full color range needed in a reef tank.

Same thing with the PC/VHO bulbs you have. They can cost anywhere from $20-$40+ each which is where I got the $300+ figure for the total change out.

This is all assuming the bulbs are old and need to be replaced. If changed within the last couple of months it can wait but I’d still get them now so you have them when it is time to change.

 

[Howdy]

okay thanks for the explanation. I'll try to find out the K rating on these if I can too. To be honest, I think they may be the street bulbs, but I need to look closer at them tonight. they look an awful lot like the link I put up in that post and I think might be those.. that would explain all the algae that I've been cleaning for the past 2 days.

okay, so based on a maximum of 1 K per hr. (10 hrs. per day operation, 365 days per year)... A maximum of 3650 K drop per year. So if I got 20,000 K bulbs, I could probably get by using them for the 3 yr. life and still be above 9000 K?? or is that not right?? I don't want to have to replace every 9 mos. if possible, so I'm just thinking here... What is the best K for coral? Is 20,000 K the best? with a minimum of 10 K??

Is the K the most important parameter that I need to be looking at in finding new bulbs?

thanks.

 

[Brenden]

The life of PC/MH/VHO bulbs can last as long as two years.

8O Never heard that before.

 

[tecwzrd]

Metal halide bulbs last an average of 6,000-10,000 hours or up to 2 years using 10-12 hours a day.

PC and VHO have a slightly shorter lifespan and can last up to 18 months.

http://www.liveaquaria.com/general/general.cfm?general_pagesid=217

Due to the color shift and the decrease in lumens they should be replaced before they burn out somewhere between 9-12 months.

 

[BillyZ]

How long they last (ie burn out) and how long before they should be replaced are two different things as well. How long before you should replace them will depend on a number of factors. Heat, Length of time they are on a day, condition of the power/transformer etc.

I use PC lights. I have 2 each white and actinic. I change them once a year. I can see a marked difference between the color and intensity when I change the bulbs. I change one set of white/blue at a time and after changing the first set one half of the tank looks much more "yellow" and dimmer than the half with the new bulbs.

 

[Brenden]

How long they last (ie burn out) and how long before they should be replaced are two different things

Definitely

 

[Howdy]

what is it about the soft light that causes algae growth?

How many WPG are ideal in a reef set-up? I'd like to add the middle MH, but I'm afraid that will be too much light on this set-up.

Update:

okay, the longer (2) bulbs are VHO (68") super antnic (don't see a wattage on these anywhere).. the ballast that said 165 Watt I'm thinking is for these 2 bulbs.

The MH are MT250DL

The tank height measures 21.5, not 22. so not sure if this is actually a 125???

so you guys would replace all the bulbs, serioiusly??

what color (or temp) should I get for the 250 MH's and the VHO's? are 6' VHO's a standard wattage?

Update 2
the ballasts and fixtures are hamilton technology the one labeled 165 W that I think is for the VHO, hooks into the larger ballast with the (2) MH 250's.

Do any of the 250 MH lamps work on this, or do I need to replace with the same bulb. It appears that these are 6500 K (Iwasaki).

 

[steve-s]

The 250 MH will work fine for that depth depending on elevation height above the water line. If it's about 8" or so your fine. The problem I see here is the tank length. A 165w VHO is 72", so with that kind of tank length, you need 3 MH fixtures, not 2. MH only covers a 2x2 foot area so you're ending up with dim spots.

FWIW, bulb burn life and spectrum life are two completely different animals. PC's last about 9-10 months. VHO 11-12 months and MH about 12-14 months. It really depends on the length of time each is run for the most part.

Cheers
Steve

 

[Howdy]

there is a fixture for another MH in the ctr., so maybe I'll take a look and see if that is an option. Otherwise I'm assuming I can put corals only on the 2' on each edge. the bulp is about a foot in on each end, so I should have 2' on each side of the 6' tank with coverage I think...

I don't understand completely here why low light or low color spectrum would cause algae. I thought too much light would cause algae?? I could understand slow coral growth, but I don't understand how that would cause algae. can someone please explain this? how low bulp illumination and/or lower spectrum (K) causes algae. thanks.

 

[seaham358]

How long they last (ie burn out) and how long before they should be replaced are two different things

Definitely

agree with this.. I like to push the limits on the bulbs but they do need to be repalced on a regular basis. 6-8 months on the VHO is what I like. I know when it time when I start to get some cyno and my corals dont' POP in the after noon. This is one area wher you can't cut corners if you want NICE corals. In a FOWLR tank its not a big deal..

 

[Howdy]

I guess I do have 3 MH (250's). the switch was broken on the middle one and after I replaced that it worked fine. I'll replace the 3 MH's right off the bat as everyone suggests here. the ballast has 2 outlets and is rather large. can I use any 250 MH bulb in these and what do you all suggest for both brand and (K).

the super antinics are totally for show, correct? if that is the case, I think I'll not replace those straight away and wait for them to burn out.

thanks.

 

[steve-s]

the super antinics are totally for show, correct? if that is the case, I think I'll not replace those straight away and wait for them to burn out.

For the most part yes, if MH is the main lighting scheme. Really depends on the light demanding animals you keep. Some LPS type corals will appreciate the proper actinic light and there may be some algae issues if the bulbs get too old. If I leave my actinics too long I know there is some sort of shift that some animals do not like because my anemone begins to move. Once the actinics are replaced, the movement stops. If this is primarily an SPS tank, no worries but I still wouldn't leave them until they burn out.

Cheers
Steve

 

[Howdy]

thanks for the info. everyone...

I've been thinking more about this while I cycle my live rock and get the tank cleaned up....

$300 for bulbs every 9 mos. seems a bit extreme for me since this is my first salt water tank.

I'm thinking of doing live rock only now and not using the MH lights at all. I'm worried about algae since I'm new to this as well. I was thinking instead to use only the two 72" VHO's. If I do this, what would you all recommend for the VHO bulbs for a live rock and fish tank? I'm assuming that a live rock fish tank doesn't need any lights, except for show.. is that right?

Can I still do some coral with this lighting (that should be 320 Watt for a 125 gal. tank)? if so, which corals. I could much more easily justify changing out $80 of lights each year and getting lower light corals.

 

[steve-s]

What's the depth of the tank?

2x160w VHO would do fine for coralline and such and a fair amount of softy species but research any LPS well before prurchasing.

Cheers
Steve

 

[Howdy]

tank depth is 22"

as far as the lights. I keep going back and forth on this. If I stick with the VHO's only, which bulbs would you get for it? what about doing 1 or 2 MH's and strategically placing the coral that needs higher light??

just an update on the overall project. I followed the advice above on the live rock. I ordered 90 lbs. from live aquaria that has been curing now for over a week. it came a day earlier than what they said and looks good. some die off and I think that is normal from what I've heard. ammonia is still at 8 ppm and it has been about 10 days with 1 water change. does that sound right?

I also ordered 120 lbs. from hirocks. 60 lbs. I think it was of the large rock and 60 of the rubble (mainly for the wet/dry filter). a full 7 days after the order, no response at all. I emailed them and they responded with a shipping number. The shipping number showed that the shipment request had just been placed, so I think they may had forgotton about me until I emailed them. 10 days and still no rock, so not overly impressive but hopefully I do get it. I'll post about how it looks. I've also ordered numerous things through DrsFostersmith.com and everything has came very quickly and prices are very good as compared to what they charge locally.

added the gfci and grounding probe and a bunch of other goodies that were suggested in the article referenced above. I see now why they say this is an expensive hobby! Finally getting close to getting the sand in and filling the tank.

 

[tecwzrd]

If you want to keep more of the life on the lr I’d do more pwc while curing to keep the nh3 below 3 ppm.

Hirocks always takes awhile to ship but usually it's worth it.