An Idea (1 Viewer)

[FireEater]

I was thinking of a way to do a big water change without the mess or the stress on everything.

I have a 65g drum I mix salt water in. What I was wondering is, can you take this drum and run an plastic icemaker hose out of it and into your sump. Maybe put a valve on the end of it to control the flow.

Next run the same type of hose out of your sump and into your yard. You can also put a valve on it to control the flow. They sell the small plastic valve at Lowes next to the hose.

I believe the icemaker hose is 1/4" and the valve is set up to where you just push the hose into one side of it and it stays. Same with the output part of it.

Now once you have your salt mix ready to go you start a siphon from the drum to the sump and from the sump to the yard. Even if you went full flow on the siphon it wouldn't be much. Though you can use both valves to adjust the flow in and out to match.

Now let the siphon run until all the water is gone from the drum. This will do a steady water change on the whole system and a large one at that. It would seem to me that it would be less messy and you would get away from having to siphon out so many gallons of water at once and then add the water to make up for it.

Maybe less of a shock to your system?

Maybe less messy overall?

Would it be effective enough for a water change on the system?

Mark

 

[dillo]

Is your sump set up to keep the new water your adding from mixing with the old water when you are making the change?. Also I don't know if you have grass or not inyour yard but 65 gallons of saltwater poured onto it will certainly kill it.

 

[FireEater]

I would leave the pump running in the sump so to circulate the water through out the system as I add it and remove it.

It seems to me that this would do a 65g water change but at what percent? Since the water will be overturning in the entire system.

Instead of my yard, I can just run the hose out and into my sewer cleanout drain.

Mark

 

[dillo]

The way I understand it is that fresh saltwater and old saltwater are going to be mixing together as you do this. Am I correct? If that is so then some of the fresh water that you will be adding will be going right back out with the old water. You would just be wasting it. Or maybe I just do not completly understand what you are doing.

 

[cparka23]

you want to siphon out the old saltwater and siphon in freshly prepared saltwater at the same time? I think you'd waste a lot of the new water in the process. the saltwater would kill your grass, too. and you'd have to worry about trapped air getting into the tube going out to the yard.. if you get air bubbles in long tubing, they can be a pain to get out especially if the tube has to go through walls, etc. it'd all be easier to just get a small pump to do some of the work. perhaps the siphon brining in the new saltwater would work well enough if you kept the reservior a little higher than the sump.

 

[ChrisB]

Wouldn't it be great if you could just do this every so often?

 

[Guest]

WOO-HOO!

 

[Niko5]

Thats how I do my changes now except I have a drain in the bottom of my sump that has a pipe that goes up to my "correct" water level then i trickle the water in the tank from my new salt water tub and as the water fills up other water overflows the pipe and drains out... im not sure if the syphon on draining the water would work because it would probly drain at a diff speed than you put it in.

Also yes you do loose a tiny bit of fresh water but say you do a 25% water change with loosing the fresh water you probly do a 23% water change.. big deal its alot less stressfull on you and your tank.

 

[FireEater]

That's what I was wondering Niko. Doing a water change like this, how much water percentage would be done.

I'm doing water changes on a total of 185g so each change is a big one. If I use 50 to 60 gallons to start with and siphon it in as I siphon out, how much of a water change would that be?

It is a straight shot from my tank to the sewer cleanout plug also, Maybe a 50' shot.

Mark

 

[robrog]

It might be interesting to do a experiment on a small scale. Using a tank of clear water and then some water with food coloring in it as your new water. Use the method described above and check the water color of the tank and the waste water afterwards. Compare that to a mixture using the standard method for water changes and see how much color differance there is. It isn't an exact measurement, but it could give you an idea of how much water use lose by the color of the tank water comparison, and how much color your waste water has. Seems like it would be easy enough to set up with a couple of 10 gallon tanks.......

 

[Guest]

use a dark color dye and a PAR meter to test difference. Less subjective then 'how much the color differes', IMHO

 

[robrog]

With all the experience looking at color charts on test kits and trying to figure out exactly how many nitrates we have, we should all be experts at color comparison by now!

 

[Guest]

Well I have one of the 10 gals, anyone have a PAR meter?

This sounds like a nice little workshop activity, for Marsh.

 

[Niko5]

Yea that would be fun.

I think what would be best... is have a 10 Gal to rep the sump and a 20 gal to rep the tank. Then pump the water from the sump to the tank and let that run. Then setup the overflow drain in the sump tank and the trickle of water w/dye in the sump tank. I think iv got a 20 gal and a pump.

 

[Guest]

fun this would be, yes
I feel a ripple in the force

 

[Niko5]

Uh oh.. a ripple in the force.. who let one go....must have been Narkon

 

[AggieBrandon]

What I do when I want to do a fairly large water change is close the return line to my tank so my tank doesn't drain any lower than the overflow teeth let it. Then I open another valve on my return pump and pump quite a bit of water out of my sump/refugium (about 20 gallons or so). Then I can refill the sump with newly mixed saltwater. Then if you want to take out more water from the display you can siphon out water down to the level of yoru corals or whatever. Then I turn my return pump back on and the tank fills back up and I can add more fresh mixed saltwater up to the level my sump is supposed to be at. I find by doing it this way I can take up to 40 or so gallons total. This equals out to about a 36% water change in my reef tank. Having a spare pump to move water between the tank and water holding tank helps alot too. However, I lean to just do a 20 gallon water change every other week or so.

Brandon

 

[Guest]

Nick if you are wanting to do this, I got a 10 you can borrow.

 

[Trey]

This can be calculated. I will have to make some assumptions, but a fairly quick excel calculation can resolve this question. I will assume 185 gallon total water volume, 65 gallons of fresh salt water added, equal in/out flows, 1000 gph recirculation rate through the sump, that the process will take 12 hours, and that no grass is harmed during the completion of the water change.

Correct my assumptions if you want to before I run the calculations. If I get the spreadsheet working correctly, maybe I can figure out a way to e-mail it to those interested.

Later,
Trey

 

[Trey]

Hello All,

I completed the calculations I promised a few days ago. I changed my approach a bit so be sure and read the assumptions carefully. I chose to use another software package to generate these results, so I don’t have a portable spreadsheet with all of the data included.

Assumptions:
Tank Water Volume = 140 gallons
Refugium/Sump Water Volume = 45 gallons
Total Water Volume = 185 gallons
Water Change = 48 gallons
Recirculation Rate = 1000 gph
Tank and refugium are well mixed
The fresh water inlet and waste outlet flows are equal.
An instantaneous water change is 100% efficient

Methodology:
I modeled the tank and refugium/sump system as continuous stirred tanks. This is a reasonable assumption for most salt water tanks given the high recirculation flow and the use of power heads, closed loops, etc. Additionally, I used nitrate as a marker to determine how much water was wasted. This is an adequate approach given the solubility of nitrate in salt water systems.

Solution:
Two primary results were determined. They are how much water is wasted using a slow water change approach as described above, and how does the introduction time impact the amount of fresh salt water that is wasted. In all cases the comparative case was a traditional water change where fresh salt water is not mixed with the tank water until the appropriate amount of “old” water is removed.

The table below shows the results of the study.

Initial Nitrates ppm 50 50 50 50 50 50
Final Nitrates ppm 38.573 38.570 38.565 38.498 38.292 37.027
Total Time minutes 5760 1440 576 60 15 0
Percent Water Change % 26% 26% 26% 26% 26% 26%
% Wasted Fresh Water % 12% 12% 12% 11% 10% 0%
Wasted Fresh Water gallons 5.72 5.71 5.69 5.44 4.68 0.00

As you can see from the results, fresh salt water is in fact wasted by this method, but if convenience out weighs cost, it is still a viable approach to a water change. The effective % water change must be adjusted according to these factors to reflect actual value of a water change. For example if you were to target a 25% water change in a 100 gallon system you would typically replace 25 gallons of water. If the time based water change method was used instead, it would require about 12% more water or 28 gallons of fresh salt water for the same effectiveness (dependent on time for the change).

I hope that helps to clarify the discussion. It may have taken the fun out of the whole thing.

Later,
Trey