mh 250 too much

[darklcd]

hey all

I am just wondering if a 250 watt mh light would be too much for my tank. Its a 25 gal (22"h x 12" w x 24"l) and I have a friend that is going to get rid of one for cheap it comes with legs and everything else.

I am also wondering if having pc lighting along with it is a good idea. He has 2 fixtures and one is just the 250 and th other has acouple pc bulbs with it would that be better or is the 250 ehough by it self

any thoughts?

 

[apollothesun]

all i can think of are heating issues, water top off evaporation

 

[Krish]

I agree...Typically you see a 250w metal halide pendant/bulb over a 2ft length of tank space anywhere from 18-24 deep.

 

[darklcd]

I thought about the water evaporation but I will be doing water changes once a week anyway so it should be ok. with my tank being 22" high I think I shoudl be ok based on what you all have said.

 

[Herefishyfishy]

250 watt MH on a 25 gallon will cause problems. Go with a 150-175 unless you plan on upgrading your tank size soon.

 

[darklcd]

just wondering what kind of problems I would be looking at?

 

[Herefishyfishy]

fighting Heat is a pain

 

[darklcd]

what I was thinking is if I hang the light a little higher up then normal it should be ok. as well the fixture has a couple built in fans that should help. i was also thinking that if I removed the heater from my tank or just kept it turned way down it might be ok

 

[Herefishyfishy]

Much of the heat is from the radiant light energy converted to heat energy, raising the temp of the water. You do NOT want daily fluctuations in the temp such as hot in the day and cooler at night.

 

[darklcd]

so bottom line this is not a good idea regardless if I hang the light higher then normal?

 

[Herefishyfishy]

It would be OK if you ran fans on the water with an ATO for the daily evaporation or a chiller in addition to a heater for night. All this would really need a temp controller to ensure no broken heater problems. That is a lot of equipment for a 25 gal. Go with the smaller wattage and will be less trouble.

 

[steven11]

Mike is right about the constant troubles. I ran a 250 over my 10 gal for a short period befor upgrading to a 36 bow front and i was constintly adding fresh water and worring about temp. I got really lucky to not have any big problems but i was checking on the tank 2 to 3 times a day. Plus i was running on the Karma account. A lot of work for a little tank. You would do your self big favors by doing the 150 or 175.

 

[knowcrap]

Much of the heat is from the radiant light energy converted to heat energy, raising the temp of the water. You do NOT want daily fluctuations in the temp such as hot in the day and cooler at night.

Personally, I don't necessarily agree with this. Our tank swings about 4 degrees between lights off (76) and lights on (80) every day...for the last two years this tank has been up and running. I have no data other than my own personal experience but there are others that agree that small temperature fluctuations are nothing to be concerend about.

As far as the lights, it probably will be overkill but it could be controled with fans and you will probably need to add top-off water to it more than one time a week (if you are not adding top-off regularly other than water changes be careful of your salinity level creeping up to a high level). Personally I run 4 x 400W standard MH in Lumenarc Mini 3's over a 180G with a few fans running over the lights.

One thing you did not mention is the tanks main inhabitants - i.e. fish only, LPS, SPS, etc. The high light may be good for SPS but probably won't be good for other corals (soft/LPS) and/or fish only...do note this is a general rule of thumb and you should check the requirements for each living creature you put in your tank.

If the deal is that good you can experiement with lights and if you decide it is too much you can use it to trade for something else (or just sell it).

 

[darklcd]

from what I hear 250 will be too much and thats ok.

I am just wondering if a t5 fixture with 4 24 watt bulbs would be enough to get down about 22" in the water to have clams on the sand or not. that is what I am trying to get is a clam or 2. They don't have to be the maximas or anything but would 4 t5 bulbs be ok?

 

[Herefishyfishy]

If you want clams yet also small tank, go for a shallower one such as a breeder.

 

[darklcd]

would t5s be enough to get though the water. I know that clams are a long shot but getting a different tank is not an option right now. I just baught this one lol. I am just wondering if 4 t5 bulbs will suport clams. I know that the maximas like rocky areas so I was thinking that I might be able to get away with having one on my live rock right at the top of the tank. is that an option

 

[Herefishyfishy]

T-5s would support Derasa clams, but keep in mind that regardless of what any store tells you, tridacnid clams of any genus are advanced level livestock. They require a lot more than just simply good lighting. Perhaps wait until your tank is mature and stable evidenced by good coral growth.

 

[darklcd]

I understand that I am going to have to wait for clams. I know that they are an advanced livestock to keep. I am just trying to not be killed by my wife at the same time lol. it was hard ehough to get a tank in my living room let alone another 400 or 500 for lighting and I can get good t5s and 250 mh from my source but thats about all that he has. thats why I am running into problems.

once my tank is up and going and is ready for clams is there any way that a maxima or another species would be ok under 4 24 watt t5s if its very near the top of the tank?

 

[Herefishyfishy]

once my tank is up and going and is ready for clams is there any way that a maxima or another species would be ok under 4 24 watt t5s if its very near the top of the tank?

Assuming everything else was excellent, yes it would be OK. Not good nor excellent growth, but probably OK

 

[darklcd]

so if I decied to eat a bit of money and get a 150 that would be the best thing to do I take it