CO2 injector recommendations?

How does this arrangement for a metal halide lamp look? It's a hydroponic lamp; as in most cases, it's far cheaper than a similar setup designed for aquaria. The main thing I'm worried about is mounting the reflector inside the tank's canopy; will heat be a problem? The canopy is acrylic. I suppose I could drill a vent in the canopy, but I'd rather not.

Well, CF has a higher light output per watt.. You would have to do a cost/benefit analysis.

I scavenged a bunch (about 20) of F96-T12 ballasts from a lighting refit, so that kind of makes my choices simple. Be on the lookout for stuff like that. The ballast is the expensive part. Anywhere somebody is doing a remodel (commercial) it pays to be inquisitive.

Where's Todd (farmertodd) when you need him? He's the only one I know with good metal halide experience. I would recommend that you pm him for some advice.

How does this arrangement for a metal halide lamp look? It's a hydroponic lamp; as in most cases, it's far cheaper than a similar setup designed for aquaria. The main thing I'm worried about is mounting the reflector inside the tank's canopy; will heat be a problem? The canopy is acrylic. I suppose I could drill a vent in the canopy, but I'd rather not.

In terms of costs, I think it goes: aquarium product --> horticulture product --> complete DIY. Also, horticulture rigs tend to be very high wattage. Even the low power ones may be more juice than you want.

If you're willing to cobble them together yourself from parts, you can build 150w MH for less than $150 each. This is possible because there are cheap Chinese ballasts and bulbs available, and because double-ended 150w MH bulbs fit in fixtures built for 300-500w halogens, which are also cheap and widely available. I have some 70w versions of this that I like a lot, but I can't give you any info on their long-term viability.

I think 4 150w MH would be a nice setup. Lots of very nice light for not too much in initial or long term costs (theoretically). Buuuuut, you have an established photoperiod and lighting enclosure for this tank, right? This means you can't move the lights up or down, run them less or more, etc. in order to adjust the lighting (However, I'm not convinced that 600w of MH would be "too much light"). So maybe a system based on many fluorescents or power compact bulbs would be easier to adjust while still keeping the tank well enough lit to be enjoyable.

Of course, you can always suppliment MH lighting with several floro tubes that run longer, but how complicated does this need to be? 55w CF tubes are pretty cheap, pretty bright, and pose less issues I think. The downside is that they will not penetrate as well in your huge aquarium. T5 might do a better job of that, but I don't have any ideas about how to get them set up without spending Aquarium Product money (that is, a lot of it).

Have you considered buying a used aquarium or horticulture fixtures? Reef forums sometimes have ads up from upgrading from lower to high wattage MH. Police auctions are a constant source of confiscated horticulture gear, but again this stuff tends to be in the 400-1,000w range.

Thanks, Mette.

This gets more complicated every day! I will look at the reef classifieds and see what I can find; if nothing good shows up in the next week or so, I'm going to go ahead with T12 fluorescents and the plants will just have to manage as best they can.

Thanks, Mette.

This gets more complicated every day! I will look at the reef classifieds and see what I can find; if nothing good shows up in the next week or so, I'm going to go ahead with T12 fluorescents and the plants will just have to manage as best they can.

Makes sense to me. Are the T12s already in there, or are you installing all new stuff?

That's where it gets kind of weird. The guy who had been taking care of the tank before had twelve T12s installed. The tank has been sitting empty since about September. Then last week, out of the blue, he comes and removes four of the T12s. I don't know if he wants to come back for the rest, and I don't know how to contact him. So currently there are eight T12s in the tank, all on one side.

I guess we'll just go ahead and act as if we're going to keep them, and if he comes back for them we'll offer to buy them from him. I don't know if this guy bought the lights with his own money, or with his club's money, and neither does anyone else, apparently. It's all very odd.

That's where it gets kind of weird. The guy who had been taking care of the tank before had twelve T12s installed. The tank has been sitting empty since about September. Then last week, out of the blue, he comes and removes four of the T12s. I don't know if he wants to come back for the rest, and I don't know how to contact him. So currently there are eight T12s in the tank, all on one side.

I guess we'll just go ahead and act as if we're going to keep them, and if he comes back for them we'll offer to buy them from him. I don't know if this guy bought the lights with his own money, or with his club's money, and neither does anyone else, apparently. It's all very odd.

Additional, undue complications -- why not? Anyhow, my enthusiasm for the T12s was mostly based on the fact that you already had them. If you think this guy is likely to come carry off the rest, it might be easier to get new lights now. If not, then definitely run what you have and add more if you think you need them.

I think this is the least complicated response I can manage: If it were my tank (God I wish it were my tank), I would DIY either four 70w or three 150w MH lamps. They could be built fairly cheaply and wouldn't cost too much long term. I really like the visual effects they produce -- regions of higher and lower intensity, shimmer from surface ripples, perfect fish-shaped shadows, etc. -- they're nothing like the even, diffuse light of fluorescents. I would probably run a few watts of some type of fluorescent lighting in the morning and evening.

There are good reasons to prefer other options over MH. So if MH doesn't appeal to you, my second choice would be normal output T8s. In the end, I think it's better to use lights you're familiar with since this won't be in your living room where you can subject things to regular tinkering.

Sorry for dragging this out -- when it come to aquarium projects, I rarely succeed at keeping it simple.

No apologies necessary; you have given me a lot of good info. Besides, I know well the urge to expand and tinker; it's a good thing I don't have any money, because I'd just spend it all on unnecessarily complicated projects. You should see my DIY drawing desk plans; they get more complicated every month, and I don't even have a place to put the thing if I did build it!

Someday I will hopefully be able to set up some big tanks in my own home, and I'll definitely try the metal halide lighting then.

This is what I'm getting. http://www.fullspect...ns_112_prd0.htm

One of these and maybe 4 T12's on the left, plus the existing eight T12's on the right.

Newt,
sorry to bump this thread but wondering where the tank stands, what did you decide to do for lighting,CO2, and substrate.. Also would love to see a pic. I am browsing thru these older threads looking for ideas and suggestions but they always seem to just end like they were forgotten about..lol.

I ended up going with the fixture in the link above on one side, and four T12 fluoros on the other side. The tank is planted with Vallisneria americana (ordered from aquariumgardens.com) and Ceratophyllum demersum (collected from Buffalo River), both of which are thriving.

Current stock includes about 7 golden shiners, ca. 4"; about 12 fathead minnows, ca. 3"; 3 warmouth, ca. 3.5", and 7 redspotted sunfish ca. 2-3.5". The minnows are from a baitshop, the sunfish from Brian Zimmerman. I also have a bunch of minnows, mudminnows, madtoms, logperch, and longear sunfish in growout tanks who will eventually go in the big tank; all these were also provided by Brian.

Substrate was put in as follows: layer of fine gravel, about 1"; layer of woodland topsoil, about 3"; layer of oak leaves, about 3"; second layer of fine gravel, about 1"; layer of creek gravel, about 2". The substrate is not as deep as the total of those figures; the leaf layer compressed to almost nothing and the soil layer has merged with the fine gravel layers.

I have a constant battle with algae in the tank. I have reduced the photoperiod, but I am limited in the amount to which I can reduce it by the fact that this is a public display tank.

My newest project for this tank is to improve the filtration. It has a built-in spillover filter in the back of the tank; the volume is a bit small for such a large tank, but more importantly, any evaporation drops the level in the filter swiftly. I have to top off the filter almost daily to keep the media wet. I would like to install some bulkheads in the bottom of the spillover filter and put in a nice big sump and a UV sterilizer. We'll see how that goes.

Substrate was put in as follows: layer of fine gravel, about 1"; layer of woodland topsoil, about 3"; layer of oak leaves, about 3"; second layer of fine gravel, about 1"; layer of creek gravel, about 2". The substrate is not as deep as the total of those figures; the leaf layer compressed to almost nothing and the soil layer has merged with the fine gravel layers.

What is the function of the initial 1" layer of fine gravel?

It seemed like a good idea at the time? I really can't recall why I put that in there.

do you have any idea what is causing the algea, could it be the lack of CO2 compared to the high lighting?

do you have any idea what is causing the algea, could it be the lack of CO2 compared to the high lighting?

If I remember correctly, it isn't planted very heavily, right? And isn't half of it unplanted?

I'd say it is moderately planted. The initial planting consisted of a small number of vals on one side of the tank, but those vals have been allowed to propogate as they please and I also added a big bunch of hornwort, which has spread as well.

I think the algae problem is likely more due to excess nutrients than anything. I have other tanks with similar proportional stock, planting, and lighting, with no algae issues at all. But those other tanks recieve more frequent water changes; the logistics of water changes on this tank mean that wc's are a bimonthly rather than weekly affair. I usually change 30-50% at once. I also believe that the filtration is inadequate. The tank has a spillover filter built into the back; I would like to install a proper sump.

I believe I will add some Cladophora as well. I have bunches of it in most of my tanks and I believe it helps compete with the smaller green algae for nutrients.

In case anyone is interested in CO2 Generation still, I'll give a thread I started about making a low-tech version. Here is the page:

http://forum.nanfa.o...wtopic=3569&hl=

I'll also bump the original thread.

-Thom