How Many Gallons?

[shanepike]

Alright, with a 90g tank which may or may not be exactly 90g and a sump with a variable depth for some or all sections, is there an easy way to measure exactly how much water I'm actually</em> putting into my system? I could just dump 5g buckets in until it was full and count how many I put in, but that seems really tedious. I suspect (and am hoping) that there's a much more straightforward way to do it.

 

[frantz]

Try this
http://www.dep.state.pa.us/dep/deputate/waterops/redesign/calculators/volcalchtm.htm">http://www.dep.state.pa.us/dep/deputate/waterops/redesign/calculators/volcalchtm.htm</a>

of course you'll have to take out for LR and sand

 

[shanepike]

That's the biggest problem, though. Trying to estimate how much volume the sand and rock take up is a hit-or-miss prospect at best and impossible at worst. I'm thinking you'd have to fill up the tank and then</em> add the rock and sand to see how much water was displaced.

 

[falos]

The sump is easy drain it and fill to its off level count the buckets
The tank can be hard for an exact amount easy way to git a rough would be
90g x 8lb =720lb - sand and rock weight divide by 8 and your sum ware in the range

 

[eagle9252]

<p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">Sometimes I post way too much info, mostly more than what’s needed. </span></span>



<p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">This is what I was told one time at a LFS and had issues with it until I slept on it and thought about it again, are you ready….?</span></span>



<p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">The tank is ?? and your sump is ?? and you have sand and rocks. Just use your DT as the total water. It will get you pretty close as the displacement of the sand and rocks in both the DT and sump.</span></span>

 

[shanepike]

I'd rather you post too much. I can always skim if it's too long

Thanks!

 

[jef4y]

The LFS is ball-park correct.

You won't get an exact volume without completely draining and refilling, measuring the exact amount of water. Period.

The rock & sand is porous and will hold a varying amount of water. The tank will hold less water than it "could" because of the overflow, so on and so forth.

In my 60 cube, plus sump, I doubt that I have 60 gallons combined. Measuring out my 150 and taking into account where the overflow starts, it's already down to like 135 gallons. That's not taking into consideration sand/rock/etc.

So in the end, you won't be exact without some extremely tedious measurements of the liquid itself, and really what would you gain at that point?

 

[texhorns98]

Check this one out. I've tested it and it get's pretty close IF you are using fairly porous rock.

 

[grouper therapy]

Fill the tank to a depth that the rock will be submerged when placed in the tank. Mark the level of the water before adding the rock and after adding the rock. Then use that number to calculate the volume.

 

[skriz]

Do you have a large enough container to hold the Sw? If so, add the rock and sand first. Then add water. Subtract what you have left from what you started with.

 

[shanepike]

Alright, I actually added the water 15 gallons at a time so I could measure it. When I got close, I started adding just a gallon at a time. Eagle wins. Total water volume turned out to be just a hair over 92g

 

[ff337]

This is easy. Grab a beer, sit in a chair, stare at the tank, and forget trying to guess how much water your turning. If your having a hard time forgetting, repeat step one as many times necessary.

 

[texhorns98]

eagle9252;770218 wrote: <p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">Sometimes I post way too much info, mostly more than what’s needed. </span></span>



<p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">This is what I was told one time at a LFS and had issues with it until I slept on it and thought about it again, are you ready….?</span></span>



<p style="text-align:left"><span style="font-family: Calibri"><span style="font-size: 13px">The tank is ?? and your sump is ?? and you have sand and rocks. Just use your DT as the total water. It will get you pretty close as the displacement of the sand and rocks in both the DT and sump.</span></span>

It may have worked this time, but how is it accurate? I'm not trying to argue...just trying to learn. For instance, a friend of mine has a 90 gallon DT, but close to a 200 gallon sump in his basement. The math you're talking about doesn't work there, unless I'm missing something.

 

[grouper therapy]

texhorns98;774044 wrote: It may have worked this time, but how is it accurate? I'm not trying to argue...just trying to learn. For instance, a friend of mine has a 90 gallon DT, but close to a 200 gallon sump in his basement. The math you're talking about doesn't work there, unless I'm missing something.

Agreed. What if you don't run a sump? If that formula works it is purely coincidental. :yes:

 

[rdnelson]

FF337;774033 wrote: This is easy. Grab a beer, sit in a chair, stare at the tank, and forget trying to guess how much water your turning. If your having a hard time forgetting, repeat step one as many times necessary.

Sounds like the perfect formula to me. Especially the "repeat step one" part.

 

[jmaneyapanda]

As stated, there's unfortunately no formula because every system is greatly variable. It can really get to blow your mind when you start calculating how much water is in the tank, sump, media reactors, skimmer, uv, plumbing, overflows, and then considering displacement.

 

[eagle9252]

That's it's callend a WAG... Wild @$$ guess. But glade that it was close

It's pronounced wog