RATIO for LB vs GALLONS.

MR PALM BEACH · 05-02-2007, 08:33 PM

Dont know if thers a answer to this question or I'm just thinking crazy. Is there any mathematical equation that can figure out the water displacement lost by added pounds. Allways wondered what the water loss would be or amount to with a certain amount of pounds (LR or LS) in there.

mps9506 · 05-02-2007, 08:50 PM

If you know the density of the rock you could calculate it, but it wouldn't be exact because of the variables in the rock structure.

MR PALM BEACH · 05-02-2007, 09:17 PM

Ahhh got cha, Ya i figured even If you knew the exact lb you could get an accurate answer. Thanks for the reply.

CATALYST · 05-03-2007, 04:09 AM

Weight to Volume conversion online.

Would this work for you?

DaveK · 05-03-2007, 06:06 AM

Actually there is no perfect way to calculate this because LR varies in density quite a bit.

However, if this is a new tank, and it's being started with SW in it, and the tank is full of water with no LR, it's easy to figure out. As you add rock, how much water did you need to remove?

You could also get a rough calculation by doing the same thing using a few representative pieces of rock and a full bucket, and measuring the water displaced, and then calculating the ratio between the rock tested and the amount of rock in the tank verses the amount of water displaced.

I should point out that you seldom, if ever, really need to get that accurate. I just usually figure that my 120 gal tank has about 30 - 40 gal of water displaced by LR and sand.

BigAl07 · 05-03-2007, 08:18 AM

Wow that's a hefty displacement Davey! That comes out to 25-30% right? Now that I am sitting here looking that's actually probably a very fair number to work with. Well there goes all of my calculations for feeding, dosing and everything else

Sounds like a good number to use as a baseline. Of course some rock are MUCH more dense than others but hey, you gotta start somewhere!!

Allen

DaveK · 05-03-2007, 10:20 PM

Quote:

Originally Posted by BigAl07

Wow that's a hefty displacement Davey! That comes out to 25-30% right? ...

Yep, it sure is. I found out the hard way. Due to a power failure about a year and a half ago, I lost everything. I had to recure the live rock, and it about filled a 50 gal rubbermaid trash can. After I removed the rock as part of setting the system back up, I only had 10 - 15 gal of water in the container. That gives me a water displacement of about 35 gal right there, and then there is any sand I use on the bottom, and any other "junk" (read equipment) I put in the tank.

Kind of makes me want a larger tank now!

05-02-2007, 08:33 PM	#1 (permalink)
MR PALM BEACH Pistol Shrimp Join Date: Mar 2007 Location: West Palm Beach, FL Posts: 250 View Gallery Karma Komment Add yours!	RATIO for LB vs GALLONS. Dont know if thers a answer to this question or I'm just thinking crazy. Is there any mathematical equation that can figure out the water displacement lost by added pounds. Allways wondered what the water loss would be or amount to with a certain amount of pounds (LR or LS) in there. __________________ And I thought buying a puppy would be to expensive! http://www.reefsanctuary.com/forums/...90g-build.html _____________________________________________ TANK SPECS: AGA 90RR Current Nova Extreme T5HO (216W) Ocean Runner 2600 (1700gph) Skimmer CSS 220 2 Hydor Koralia 4(1200gph) Sump 29g WWW.PBMAS.ORG Check out more pics of my build here In the gallery.

05-02-2007, 08:50 PM	#2 (permalink)
mps9506 Totally back Join Date: Jan 2004 Location: Wilmington, NC Posts: 8,525 View Gallery Karma Komment	Re: RATIO for LB vs GALLONS. If you know the density of the rock you could calculate it, but it wouldn't be exact because of the variables in the rock structure. __________________ Mike Reefkeeping Since '99 Help Build Reefpedia Premium Memberships Available! Support Reef Sanctuary Sponsors

05-02-2007, 09:17 PM	#3 (permalink)
MR PALM BEACH Pistol Shrimp Join Date: Mar 2007 Location: West Palm Beach, FL Posts: 250 View Gallery Karma Komment Add yours!	Re: RATIO for LB vs GALLONS. Ahhh got cha, Ya i figured even If you knew the exact lb you could get an accurate answer. Thanks for the reply. __________________ And I thought buying a puppy would be to expensive! http://www.reefsanctuary.com/forums/...90g-build.html _____________________________________________ TANK SPECS: AGA 90RR Current Nova Extreme T5HO (216W) Ocean Runner 2600 (1700gph) Skimmer CSS 220 2 Hydor Koralia 4(1200gph) Sump 29g WWW.PBMAS.ORG Check out more pics of my build here In the gallery.

05-03-2007, 04:09 AM	#4 (permalink)
CATALYST Reef Lobster Join Date: Mar 2007 Location: SoCal Posts: 1,442 View Gallery Karma Komment	Re: RATIO for LB vs GALLONS. Weight to Volume conversion online. Would this work for you?

05-03-2007, 06:06 AM	#5 (permalink)
DaveK Reef Lobster Join Date: Nov 2003 Location: Philadelpahia, PA Posts: 1,357 View Gallery Karma Komment	Re: RATIO for LB vs GALLONS. Actually there is no perfect way to calculate this because LR varies in density quite a bit. However, if this is a new tank, and it's being started with SW in it, and the tank is full of water with no LR, it's easy to figure out. As you add rock, how much water did you need to remove? You could also get a rough calculation by doing the same thing using a few representative pieces of rock and a full bucket, and measuring the water displaced, and then calculating the ratio between the rock tested and the amount of rock in the tank verses the amount of water displaced. I should point out that you seldom, if ever, really need to get that accurate. I just usually figure that my 120 gal tank has about 30 - 40 gal of water displaced by LR and sand.

05-03-2007, 08:18 AM	#6 (permalink)
BigAl07 Do I look as lost as I am Join Date: Mar 2007 Location: Waynesville, North Carolina Posts: 21,549 View Gallery Karma Komment Add yours!	Re: RATIO for LB vs GALLONS. Wow that's a hefty displacement Davey! That comes out to 25-30% right? Now that I am sitting here looking that's actually probably a very fair number to work with. Well there goes all of my calculations for feeding, dosing and everything else Sounds like a good number to use as a baseline. Of course some rock are MUCH more dense than others but hey, you gotta start somewhere!! Allen __________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~ *Live Rock Rubble will do the SAME thing as Bio-Balls and is NOT a suitable replacement for BIO-BALLS in a Reef System! It's ALL gotta go!!* Nitrate (NO3) reduction is directly proportional to percentage of Water Change. Allen's home-made formula...currentNO3-((%WC.01)currentNO3)=finalNO3 (thanks Luukosian) This means if you change 50% of your total water volume (That's EVERYTHING) you'll get a net reduction of (NO3) somewhere around 50%. Ask me about how to increase your REEF budget without going without FOOD!!* Big Al's 10g Julie's (BigAl's Gal) 6g NanoCube Gone but not forgotten BigAl's Slow 90g Tank Chronicle Allens OFFICE 12g Nano-Reef

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