Big or Bigger tank with my current lighting?

[plasticine]

I currently have a 38 gallon tank (36x12x20) with a 36" 2x150W Metal Halide fixture.
I want to upgrade my tank to something bigger and want to find out what the max size I can go to while still using my existing lighting setup. The 2 tank sizes I am leaning towards are:
75G - 48x18x20
90G - 48x18x24
The differences between the 2 are in the height. I would rather go to the 90 if possible but want to hear what people think and why.
I am pretty sure that someone will ask me what I would like to keep in the tank. I tend to lean towards not limiting myself, and love to be able to keep different kinds of corrals. Id I will try to reverse the question. What can I NOT keep based on the tank size and lighting config?

Any other thoughts or configs are very welcome.

 

[reefiness]

of your two choices i would say the 75 gallon but you wouldnt only be able to keep clams and sps in the middle of the tank up high, although a 40 breeder would be your best choice IMO because it would give you more surface area with the same 36" length

 

[plasticine]

ok, so going with the breeder route, what about the 65 gallon? It will measure 36x18x24. This would increase the surface area, but it would also be slightly taller while still maintaning the 36" length. Seems like a good comprimise, no?
I don't know if this makes a difference in determining the intensity of the light, but I am using a sunpod fixture with 300W HQI total ( 2x150W ) that would be sitting about 8 inches from water on legs.

 

[gtiguy]

I agree a 65g tank would be your best bet...it takes a 36" fixture for most 65g's ( i would know this is my current setup) and i recently just upgraded to a single HQI MH pendant 250w 20k and wow what a difference from PC & T5's lol ....and im only using 1 bulb, imagine the growth you would have using the 2-150wtts...would work out pefect!

 

[fishgeek01]

the intensity of your light will be cut in half for each 12 inches of water that it travels through or so i have been told, so the bottom half of your tank will only be getting the equivalent of 150 watts. you could add a power compact actinic, or 50 50 to help off set this, they make some very nice retro, or slim line fixtures for that reason but i think it will work out well for you either way...

 

[reefiness]

i would still go with the 40 even though its only adding 4 gallons its giving you 150% of your previous surface area. plus 150 watt lights are not really the best choice for a 24" tank. they are only really good for tank up to 16-18" for the 24" you would need a 250 watt. and if you did choose to do the 65 with your current lighting you would only be able to have sps and clams in the top 1/3 of the tank and it may be difficult to get your rocks up that high.
plus the only diference really between the 65 and the 40 is 1 extra small fish and bigger water changes so i think that the 40 would be a much better option...

 

[reefiness]

Originally Posted by Fishgeek01
the intensity of your light will be cut in half for each 12 inches of water that it travels through or so i have been told, so the bottom half of your tank will only be getting the equivalent of 150 watts. you could add a power compact actinic, or 50 50 to help off set this, they make some very nice retro, or slim line fixtures for that reason but i think it will work out well for you either way...
actually it would only be like a 75 watt on the bottom because you need to cut the wattage of the single light in half not the whole fixture

 

[gatorwpb]

I have the Sunpod 2x150 on my 65 AGA and I love it. I have lots of rock work, so any coral that need high light will be put higher in the tank. At most Ill only have a few sps so its not a problem at all.
Originally Posted by Fishgeek01
you could add a power compact actinic, or 50 50 to help off set this, they make some very nice retro, or slim line fixtures for that reason but i think it will work out well for you either way...
Fishgeek, the slim line kit, is that something that can be attached to the Sunpod?
I have my eye on some 21w 36" T-5 actinics for some extra color and wattage that appear to be able to attach to my fixture.

 

[plasticine]

GatorWPB/GtiGuy, do you have any pics and stock list so that I can see what you guys have accomplished with your setup?

 

[gatorwpb]

Ive got very little so far...
Only a Red BTA and 2 Onyx Clowns.
But I plan on getting some LPS this weekend.

 

[jmick]

I'm in the process of setting up a 125 gallon sps tank and I have the lighting now, going with 3 250 watt 10K HQI with another 220 watts of VHO for color. However, I am probably going to wait till later this year or early spring to finish it up but was considering ripping the VHO out of my current 55gal and putting in 2 250Watt 10K HQI....worried this might be way over kill...any thoughts?

 

[devaji108]

I had 2x 175 HQI MH on my 90 and love it! so did the anenomies sp?
but any way what I was going to say is:
if you are going to up gread that do it right! get the tank that you will still want 5 years down the road.
it's a pain to upgrade every year to a bigger tank because your fish are out growing the tank/ want more room for aqua scaping/ more corals ect...
yes you will pay more up front but it will be worth it in the end.
there are some great deals out there on big tanks if your check things out you just might run across a great deal.
just my .02
good luck!
PS got a 240 about six months ago and love it.

 

[plasticine]

That is a good point. One of my problems right now is that I am always chasing my preferred setup but not having the money to do it all at once. Even if I went with my original want, which was the 90 gallon, it might be a little large to be able to keep everything, but I would just need to upgrade the lights eventually and be able to keep what I want.