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  #26  
Old 11/28/2005, 08:09 PM
Randall_James Randall_James is offline
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Then all you did was move the drain hole up from the original posistion, I do not see any advantage to the change. The nice part about the lower drain hole is that you technically have a full time water change going on (small amounts a lot of times) and from what I have read, this is more desireable than larger infrequent changes.
I change 34g of my 100G system weekly and 20 per week on my 24g nano. My 125 gets about 15 (fo), I wish I had a floor drain
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  #27  
Old 11/28/2005, 08:39 PM
Anthony Calfo Anthony Calfo is offline
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kmleah... FWIW, its sounds to me like the long way around the barn, at best, and frankly... a host of problems beyond the challenge to plumb more likely.

I think you might be missing our point here... or we are missing yours.
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  #28  
Old 11/28/2005, 11:50 PM
Biotoper Biotoper is offline
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Hi Anthony,

Thanks for coming out to Boston last week - it was a great talk, although I had to run out before the end.

Anyway, this sounds like a good system, but I don't see how it can be run truly constantly. Not sure how frequently you could have the pump go, but too frequently or in too small volumes each time and the auto-top-off would not function very well, resulting in increasing salinity. Correct?

I was throwing around an idea of potentially doing something similar to pH monitor-based CO2 injection system, by hooking up a dosing pump to a digital salinity meter (I'm no electronics expert, so have no real idea how to do this). To maintain salinity at the target leve, the pump would dose water, but it would be hooked up to brackish water rather than RO/DI, so it would need to overcompensate the evaporation to maintain salinity, resulting in excess water out the overflow drain.

Ryan
  #29  
Old 11/28/2005, 11:59 PM
Anthony Calfo Anthony Calfo is offline
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thanks kindly Ryan... Boston was a truly wonderful time/club.

As per your salinity concerns... 'twas answered/addressed earlier in the thread:

"Now you may be wondering... isn't that slight overun (<1/2" over float switch level) adding a little bit of salt to the tank and increasing my salinity slowly over time? Well... theoretically yes. But if you will worry about that, then are you also calculating the similarly lost salt due to salt creep? Heehe... point is, either way its a small amount of salt. And either way, with or without salt added or exported (creep)... you still need to make slight corrections over time to the tank by checking salinity. If its a big deal (large sump)... you can compensate then by making your new seawater used for auto-water changes just slightly less saline."

Indeed... without a WCD, your salinity can/will still change and stray over time through various habits (kalk dosing, salt creep, misadjustments on make up water, etc). We are always and often using our hydrometers/refractometers for various things. So for the huge time savings and benefits of a WCD... the occasional check and tweak of salinity is a small matter.
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  #30  
Old 11/29/2005, 01:21 AM
Biotoper Biotoper is offline
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I caught your point that continual evaporation of that extra 1/2" that's not topped off will drift salinity up (not accounting for other salt export from creep, skimmer, spray, etc).

My point was just that the surge from the wc has to be infrequent enough so that the 1/2"+ evaporates and you get some FW top-off. In my 20g nano, daily evap is ~1/4" - so with daily SW inputs to a 1/2" high drain, the auto-top-off would never trigger! In other words, this system probably has some minimum tank size limit to work.

In fact, I guess I could get rid of FW top-off and just use your WCD but with brackish water instead of SW. The equation is something like:
salinity of WCD water = target salinity * (1 - e/(e+x)); where e equals estimated %evaporation per day and x equals the target %water overflow per day.

Having a salinity meter-controlled system would be much better, but I don't know if it's possible (and much more expensive for equipment)

Ryan
  #31  
Old 11/29/2005, 01:50 AM
Anthony Calfo Anthony Calfo is offline
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More often... folks with WCD systems simply make their WC water slightly less saline to (over)compensate for the diff... unlike a meter (hobby grade salinity meters have been historically unreliable/inaccurate), the adjusted SG water is at least reliable (cannot fail) and is simple enough.
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  #32  
Old 12/03/2005, 02:07 PM
Kathy55g Kathy55g is offline
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However, if your WC water is less saline, it will be less dense than the tank water, causing it to rise in the water column, so the water you skim off down the drain will partially be new water, defeating the purpose of the automatic water change system.

It would be better to manuallly adjust the salinity back where you want it by removing some saltwater and replacing it with fresh on occasion.
  #33  
Old 12/03/2005, 02:11 PM
Kathy55g Kathy55g is offline
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Quote:
Originally posted by Anthony Calfo
kmleah... FWIW, its sounds to me like the long way around the barn, at best, and frankly... a host of problems beyond the challenge to plumb more likely.

I think you might be missing our point here... or we are missing yours.
Perhaps I did miss the point. Your point was that this is for Automatic water changes, not simply easy ones (my point). Conceivably, one could put both the return pump and the water change pump on a DAY/Night timer to turn off the return pump when the water change pump came on.
  #34  
Old 12/03/2005, 02:25 PM
Kathy55g Kathy55g is offline
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Quote:
Originally posted by Randall_James
Then all you did was move the drain hole up from the original posistion, I do not see any advantage to the change. The nice part about the lower drain hole is that you technically have a full time water change going on (small amounts a lot of times) and from what I have read, this is more desireable than larger infrequent changes.
I change 34g of my 100G system weekly and 20 per week on my 24g nano. My 125 gets about 15 (fo), I wish I had a floor drain
Advantages: If power outage occurs, pipes drain to sump and water is contained there because the drain hole is just above this level. When power comes back on, typically when I am not around, the water will still be there, not down the drain. Return pump will resume its job, I hope.

Disadvantage: I must be there to conduct water changes, unless I put both the return pump and the WC pump on day/night timers to turn one off while the other is running.

I'm going to look into the solenoid thing, though.
  #35  
Old 12/03/2005, 02:42 PM
Anthony Calfo Anthony Calfo is offline
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"Disadvantage: I must be there to conduct water changes"

... you see, that's the not-so-automatic part of your automatic water change system
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  #36  
Old 12/03/2005, 06:09 PM
Kathy55g Kathy55g is offline
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Gotcha!
  #37  
Old 12/03/2005, 09:14 PM
Randall_James Randall_James is offline
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Quote:
Originally posted by kmleah
Gotcha!
Not sure I understand what you mean "gotcha"?,

this is an automatic water change system, not a "Gotta be there" water change. Also the "solenoid" program creates another point of failure and then 2 more timers? If you are going that route, there is an even easier way to do this. But again defeats the purpose of this job

If you have power failure, you lose 2 to 4 gallons, the system can make that up pretty easily when it has a 35G reservoir behind the fill system.

The idea is keep it simple, reliable and fail safe. Otherwise you just may as well break out your python and drain the thing by hand.

Thread title "How to plumb an automatic water change system!"
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  #38  
Old 12/04/2005, 12:36 PM
Biotoper Biotoper is offline
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Quote:
Originally posted by kmleah
However, if your WC water is less saline, it will be less dense than the tank water, causing it to rise in the water column, so the water you skim off down the drain will partially be new water, defeating the purpose of the automatic water change system.

It would be better to manuallly adjust the salinity back where you want it by removing some saltwater and replacing it with fresh on occasion.
If the less-saline new water was dripping into the main tank at a relatively slow rate (dependent on the difference in salinity of the new water compared to the tank, and the estimated evaporation rate for the system), and the overflow drain was in the sump below, the mixing would be sufficient to still make the water change system pretty efficient. I'm talking a slow drip system, like those used for FW flow-thru racks, rather than the on/off pump system you and Anthony are discussing.

One idea would be to incorporate a rotifer tank in this system. Something like:
a. At the top, a 10g tank with new water at ~1.019 and frozen phyto added manually each day, dripping into -
b. 2 2g rotifer bottles (for redundancy in case one crashes), overflowing into -
c. the main tank at ~1.024, overflowing into -
d. sump, with overflow drain to sink, or enough extra height so you can manually remove water every few days when you add new SW to the 10g on top.
You've got auto-water change, -top off and -rotifer feeding all in one. You'd need to check salinity regularly, and keep a careful eye on the roti pops as you would with any live culture.

Ryan
  #39  
Old 12/04/2005, 01:00 PM
Randall_James Randall_James is offline
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Quote:
Originally posted by Biotoper
If the less-saline new water was dripping into the main tank at a relatively slow rate (dependent on the difference in salinity of the new water compared to the tank, and the estimated evaporation rate for the system), and the overflow drain was in the sump below, the mixing would be sufficient to still make the water change system pretty efficient.
As I recall, Anthony did a chart about this. Am not quoting the chart but it essentially stated
100 Gallon tank
100 Gallon water change = 100% water change
100 one gallon water changes = 90% water change

I think, I can not find the chart now but hey that is plenty effcient if I am even close to his chart.

ON the roti feeder, couldnt you just keep this system seperate from the auto top off? What I mean is that the auto topoff is pretty important (even more so when on vacation, and the only reason I had to make one btw) I like the idea but again the KISS principal is sort of the goal here? Neat concept however.. As long as it would not contribute to the failure rate of the system (key word was "careful eye on roti pops")
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  #40  
Old 12/04/2005, 01:54 PM
Biotoper Biotoper is offline
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Quote:
Originally posted by Randall_James
As I recall, Anthony did a chart about this. Am not quoting the chart but it essentially stated
100 Gallon tank
100 Gallon water change = 100% water change
100 one gallon water changes = 90% water change

I think, I can not find the chart now but hey that is plenty effcient if I am even close to his chart.

ON the roti feeder, couldnt you just keep this system seperate from the auto top off? What I mean is that the auto topoff is pretty important (even more so when on vacation, and the only reason I had to make one btw) I like the idea but again the KISS principal is sort of the goal here? Neat concept however.. As long as it would not contribute to the failure rate of the system (key word was "careful eye on roti pops")
The problem is that the continuous drip from the top would result in the sump level slowly rising, so there's no where to set-up a water-level-controlled auto-top off. That's why I thought of using less saline water in the drip to (try to) keep salinity constant given an estimated level of evaporation (salt creep/spray is very low in my current setup, but that would be another more-difficult-to-measure issue).

In terms of failures, there's no electricity involved at all in the water change/top-off system (just the sump pump). As long as the sump can hold the main tank overflow w/ pump off + ~14g, if I drop dead it still won't overflow.

The roti culture will be tricky - I haven't read about anyone having it auto-drip to the main tank, so that might be a problem. If it crashed, at worse I'd be dripping frozen phyto water straight to the main, which isn't bad (I'm staying away from growing live phyto in the top 10g - I think frozen concentrate will be easier and better).

On %water change, I think if you keep total % the same (e.g. 1/24% every hour, 1% a day, or 7% a week) and assume removal or excretion of X molecule is constant (e.g. not concentration-dependent), the concentration of X molecule in the water asymptotes at the same concentration. There's an article in Advanced Aquarist that shows graphs for this.

Ryan
  #41  
Old 12/04/2005, 02:53 PM
Randall_James Randall_James is offline
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kmleah
The salinity of the water for the change system is offset by the temperature. The cooler water is going to drop to the bottom of the tank. By the time it warms it will have diluted enough with tank water to offset the salinity issue. ( I had to try this first btw in the kitchen, my better half thinks I have stepped of the deep end)
Quote:
Biotoper
The problem is that the continuous drip from the top would result in the sump level slowly rising
That was the first thing addressed by the "drain" at or just above the auto top off level in the schematic.
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  #42  
Old 12/05/2005, 12:06 AM
Kathy55g Kathy55g is offline
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Quote:
Originally posted by Randall_James
Not sure I understand what you mean "gotcha"?,


sorry, I meant that now I understand the point.

Quote:

this is an automatic water change system, not a "Gotta be there" water change. Also the "solenoid" program creates another point of failure and then 2 more timers? If you are going that route, there is an even easier way to do this. But again defeats the purpose of this job

If you have power failure, you lose 2 to 4 gallons, the system can make that up pretty easily when it has a 35G reservoir behind the fill system.
Unfortunately unless the power failure happened to coincide with a water change time on the automatic system, the sump, lacking a solenoid on the drain 1/2 inch above top off level would refill with RO/DI topoff water.
I am beginning to think that keeping it simple, means at least turning a couple of valves by hand while I watch.
  #43  
Old 12/05/2005, 12:20 AM
Kathy55g Kathy55g is offline
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Quote:
Originally posted by Randall_James
kmleah
The salinity of the water for the change system is offset by the temperature. The cooler water is going to drop to the bottom of the tank. By the time it warms it will have diluted enough with tank water to offset the salinity issue. ( I had to try this first btw in the kitchen, my better half thinks I have stepped of the deep end)

That was the first thing addressed by the "drain" at or just above the auto top off level in the schematic.
The reason that warm water rises above cooler water is that warm water is less dense than cool water.

The reason that more concentrated salt solutions sink below less concentrated salt solutions is that salt adds density to the water. More salt, more dense. Less salt, less dense.

When you tried this for yourself in the kitchen (my husband would sympathize with your wife) did you try only the temperature test, only the salinity test, or did you test both salinity and temperature differences to see how they offset each other? It would be interesting to see how both lowering the salinity and the temperature would affect water levels. How much temperature offsets how much salinity? How did you distinguish one "kind" of water from another to determine the result?

Thanks,
Kathy
  #44  
Old 12/05/2005, 12:39 AM
Kathy55g Kathy55g is offline
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Quote:
Originally posted by Biotoper

One idea would be to incorporate a rotifer tank in this system. Something like:
a. At the top, a 10g tank with new water at ~1.019 and frozen phyto added manually each day, dripping into -
b. 2 2g rotifer bottles (for redundancy in case one crashes), overflowing into -
c. the main tank at ~1.024, overflowing into -
d. sump, with overflow drain to sink, or enough extra height so you can manually remove water every few days when you add new SW to the 10g on top.
You've got auto-water change, -top off and -rotifer feeding all in one. You'd need to check salinity regularly, and keep a careful eye on the roti pops as you would with any live culture.

Ryan
Interesting idea Ryan; how did you know I am starting to raise clownfishes and the system I am noodling over is a grow-out for them?

The problem I see is the rotifer tanks overflowing into the main tanks. Rotifers pollute their water beyond belief, and were I to simply let them overflow with their water into my larval tank, the larvae would die very quickly from the incredible pollution. I prefer to spend the time to filter and enrich my rots before I feed them to my babies. I would not overflow them with their nasty water into my display tank either. Yours is not a bad idea. It is an idea that we have all noodled over at one time or another, but there is no getting around the funky water issue, so I'll just keep doing it the old fashioned way.

I keep my rots in water jugs by the basement sink so I can filter off some rots, do water changes on the jugs, feed and treat for ammonia, and wash up the equipment very conveniently.

Cheers,
Kathy
  #45  
Old 12/05/2005, 01:07 AM
Randall_James Randall_James is offline
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Kathy
I tested as it would be in the tank. I set the 81 degree water at tank salinity 1.026 and the 78 degree water at 1.024 (water had some dye in it so I could see it) I dripped the water in from 1" above water level and it sank to the bottom It did appear to loose some of the content on the way down but the vast majority of the new cooler, lower salinity water did make the bottom of the tank.

I dripped 1 gallon of the cooler less saline water into a 10 gallon tank full of water fresh out of my 75G sps tank. (water change day) so it only cost me 1 gallon of good water , I am as cheap as I am curious

I have read your thread and your endeavors with the fish fry in the breeders forum I think it was.

Quote:
I am beginning to think that keeping it simple, means at least turning a couple of valves by hand while I watch
Well making it "Fail safe" means watching it. I personally like the "fail safe" method. I would open my valve, start my pump on a 1 hour timer or what ever it needed and walk away. Leave a flag on the fishes food bin that the valve is open so that I do close it sometime in the next 24 hours. I am a tough sell on anything being fully automated. I have tried them all, AC controller 2 was a nightmare and I am greatful I did not loose my tank to it.
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Last edited by Randall_James; 12/05/2005 at 01:17 AM.
  #46  
Old 12/05/2005, 08:02 AM
Kathy55g Kathy55g is offline
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Wow, great experiment, and thank you for telling us the details. It is good to know that that combination works.

I am also as cheap as I am curious.

I hope you enjoyed the third attempt thread. The fish are nice and healthy and starting to be ready to leave home. I don't know whether to be happy or sad.

The fail safe method you describe is probably my best bet: semi automated for the absent minded.


thanks,
Kathy
  #47  
Old 12/05/2005, 09:43 AM
Biotoper Biotoper is offline
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Quote:
Originally posted by kmleah
The problem I see is the rotifer tanks overflowing into the main tanks. Rotifers pollute their water beyond belief, and were I to simply let them overflow with their water into my larval tank, the larvae would die very quickly from the incredible pollution. I prefer to spend the time to filter and enrich my rots before I feed them to my babies. I would not overflow them with their nasty water into my display tank either. Yours is not a bad idea. It is an idea that we have all noodled over at one time or another, but there is no getting around the funky water issue, so I'll just keep doing it the old fashioned way.

I keep my rots in water jugs by the basement sink so I can filter off some rots, do water changes on the jugs, feed and treat for ammonia, and wash up the equipment very conveniently.

Cheers,
Kathy
Thanks for the advice. I didn't know you were breeding - I have some filter-feeders in my tank and planning on getting an Ocellaris pair, so I was thinking roti culture.

One question I have is whether the roti jug water would get that funky if ~0.5g of new SW was trickling through it per day? Of course, a population of X density would create the same amount of waste w/ or w/o flow-thru, but it would be less concentrated in waste than if you had added water straight from your isolated roti jug. But I would really like to find someone who's tried a flow-thru roti system (success or failure).

Cheers, Ryan
  #48  
Old 12/05/2005, 10:31 AM
Randall_James Randall_James is offline
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Quote:
Originally posted by kmleah
Wow, great experiment, and thank you for telling us the details. It is good to know that that combination works.

I am also as cheap as I am curious.

I hope you enjoyed the third attempt thread. The fish are nice and healthy and starting to be ready to leave home. I don't know whether to be happy or sad.

The fail safe method you describe is probably my best bet: semi automated for the absent minded.


thanks,
Kathy
Watching your thread very carefully actually, I have mated yellow strip maroons that I want to breed but I do not know where to start, you are thankfully helping me lay out some idea of how to go about this thx
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  #49  
Old 12/05/2005, 10:07 PM
Kathy55g Kathy55g is offline
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You are most welcome Randall and Ryan. Both of you may want to check out Joyce Wilkerson's Clownfishes book. And if you are going to culture phyto (wait, that's a different thread) , and/or rots, the Plankton Culture Manual by F. Hoff is good info also. Clownfishes is everywhere, but Florida Aqua Farms has the culture manual as well as other great things like live cultures, and mesh filters. Were I starting out, I would save money and buy the kit. I chose to be cheap, bought a little at a time, and ended up paying big time in shipping costs etc.

Hope this helps, and sorry to hijack. The topic of this thread is :
AUTOMATIC WATER CHANGES.


Sorry Anthony.
Kathy
  #50  
Old 12/22/2005, 02:51 PM
Casperson Casperson is offline
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Cutting holes in acrylic

Anthony, just got your book!
Great stuff! Makes Sprungs books look like a beginner. :-) Hehehe, just kidding Julian.

Could be off the thread here, but it's my first post!
I've read every thread in regard to CLM's but could not find anything on what tool to use to
cut holes into acrylic. I have an existing 55 gal Tenacor acrylic tank with only one floor hole in it, the old corner overflow. It's filled with water and coral. I don't want to empty it. I would like to cut some holes where they should be near the top, to add additional water flow. Along with that I would like to add a CLM for better water circulation. Right now I'm using the old "Power heads in the display technique":-)

So let me have it! I guess after 15 years I'm a beginner again. :-)

Peace

Tom C
 

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