turnover in 75

timrandlerv10 · #1 09/20/2007, 04:34 PM

i will be starting my 75 here pretty shortly (heh...i've said that before!) and one of the last things i have to take care of is flow.

there will be some from the return, but not that much, so i need to put something in to get the right amount and shape for lps, zoos, 2 nems.

i've seen scwds, OM squirts, koralias, etc.

if you had it to do all over again from scratch, what would you get for my 75 with those inhabitants?

thanks!

tim

oh, and start thinking about lights! early leaders look like 3x175 mh 20000k with lunars

Tomoko Schum · #2 09/20/2007, 07:10 PM

Why 3 x 175? Three bulb fixture is usually 72 inches long. Isn't your 75G tank 48 inches long? You can do a DIY set up in your canopy, but remember each bulb covers 2 feet x 2 feet area.

A lot of people debate over strong powerheads vs. a closed loop. It's really a personal preference matter. They both have pros and cons.

I understand that Koralia is coming out with a controller like a Tunze's. However, I heard that the older koralias that have been sold in the market so far do not work with it

Tomoko

timrandlerv10 · #3 09/20/2007, 08:20 PM

hmm...yes, yes it is.

2 just doesnt seem sufficient--350 watts for 75 gallons...

what would you say are the top two pros for each method? top two cons?

prncalbrt · #4 09/20/2007, 10:09 PM

i have two 400 watt 20k metal halides on a 90g so your 2 175 will do just fine....IMO

kiran523 · #5 09/21/2007, 11:36 AM

I'm running 2 250 MH's aside from my actinics on my 72 bowfront corner. It it 48" at it's widest point. Do you want to stay with 175's for any reason? If your going to have SPS then from what I've read you need to have 30-40x turnover. This could be done cheaply with a MJ 1200 and the 1600GPH mod kits from premium. Then you could hook them up to a wavemaker with no problem. At the same closed loop sounds nice.

btw how is your foxface doing?

Tomoko Schum · #6 09/21/2007, 12:30 PM

2 x 250W will be plenty to grow SPS in 75G tank and zoanthids and LPS would be just fine in the middle to lower part of the aquarium.

As for main pro's and con's, a set up with powerheads offers much lower running cost. A closed loop system requires a strong pump that consumes more power. The disadvantage is the sight of the powerheads. A closed loop system has a cleaner look for sure.

An aquarium shop owner and an aquarium maintenance person mentioned that they have seen a number of close loop systems come apart and cause disasters. That would be the worst nightmare in my book. You need to glue these joints really well.

Tomoko

timrandlerv10 · #7 09/21/2007, 12:55 PM

the reason i was going to use 175 is that i already have three of them

i just thought about the closed loop--i need another pump, and another pump either in the sump or on the floor makes more noise than a PH in the tank right? that might be the decision point right there.

my foxface, as it turns out, is not a foxface rabbitfish--he's a foxfaced chickenfish. every time somebody other than me comes in and looks at the tank, his colors melt, he flares his dorsal fin, and hides by the small powerhead in the back of the tank. he's deathly afraid of visitors...go figure

do you think it would work if i put them 12" apart? i know that wouldnt be as efficient as 2x250, but the wattage is still fairly close.

Tomoko Schum · #8 09/21/2007, 12:59 PM

Does your tank has a center brace? If so, you would be better off using just two lamps.

Tomoko

timrandlerv10 · #9 09/21/2007, 01:07 PM

yup.

good call.

i wonder how hot my 10g would get with a 175 over it...

[JUST KIDDING]

unless you think i can?

kiran523 · #10 09/21/2007, 01:19 PM

I have a center brace in my tank as well as some plastic covering a small portion of the back. I'm thinking of cutting it off and replacing it with clear plexiglass so I can get better light penetration.

Marvin's Reef has a 250MH hanging over his 29 nano with a sump. He has some really high end corals in there and they look really good.

timrandlerv10 · #11 09/21/2007, 01:31 PM

175w MH about 8-10" over the top of the tank would be ok as far as heat is concerned?

Tomoko Schum · #12 09/21/2007, 01:52 PM

I used to run 250W over 29G myself. That's a lot of light, but 29 is 18 inches tall, only 2 inches shorter than 75. 10 gallon on the other hand is only 12 inches tall. I think a 70W would be fine for 10g tank as long as temp can be managed. The temp used to go pretty high on 29G although a large fan over the sump helped a lot.

Tomoko

timrandlerv10 · #13 09/21/2007, 03:44 PM

hmm...how about 175 18" over a 10?

Siffy · #14 10/01/2007, 09:12 PM

The distance the light travels through air doesn't affect its intensity as much as water will. But it will affect heat. The problem with having a light 18" above the water surface is it will spread so much most of it will shine outside the water and be wasted energy effectively.

As for turnover/movement, it's also more how it's used than how much is use. 8ball had a thread about his closed loop a lil while back that explains it well. He has an Oceans Motions unit. It uses less electricity and a smaller pump which is cheaper to buy initially than a larger pump by moving the same amount of water in that area intermittently, but it adds the cost of another piece of expensive equipment.

timrandlerv10 · #15 10/01/2007, 09:20 PM

thanks!

Tomoko Schum · #16 10/01/2007, 10:07 PM

Quote:

The distance the light travels through air doesn't affect its intensity as much as water will.

I don't think it's quite correct in our aquarium situation.

According to Dr. Sanjay Joshi, in our reef aquariums which is only 24 to 30 inches deep, the amount of light lost to absorption by the water is quite small. The primary cause of light drop off is due to the "inverse square law". This drop due to the distance from the source of light is much higher than the absorption in the water.

I still would not use a 175W bulb over a 10 gallon tank if only a 70W bulb suffice, considering the amount of energy it wastes (and the amount of running cost as well).

Tomoko

dave3112 · #17 10/02/2007, 08:17 AM

When I was in California I had a 175 20k over my 16gal bow front. The bulb was about 8" off the top and I had a small clip on fan blowing across the top of the water when the lights were on. The temp. stayed pretty steady at 79 deg.

Dave

stolaas · #18 10/04/2007, 12:03 PM

I use two 250w MH over my 150g tank which is 31in tall and I have plenty of light reaching the bottom of the tank. My SPS are about in the middle of the tank and are growing very rapidly. the turbility of the water will make a big difference in the amount of light getting to the bottom. If you are using a high turn over rate then your water will stay much clearer and turbility will really low.