# Automatic Water Change System



## DJRansome (Oct 29, 2005)

I am planning a 4-tank rack in the basement office.

I've read a lot of articles and watched some videos about fish rooms. I think I know what to do.

My question at the moment is about draining the water. It seems like the hot set-up is to have the tanks and sumps drilled near the top. Install a bulkhead in each. Drain the tanks to the sump and the sump to outside via gravity.

Any reason not to use flexible tubing (as opposed to PVC say)?

What diameter drill-holes, bulkheads and tubing/pipe would you use?

I don't want to mess up the tanks.


----------



## 13razorbackfan (Sep 28, 2011)

You going to post pics when done? What size tanks are you talking about?


----------



## TJL (May 23, 2011)

I have a small fish room with out a good drain or w/c system. I use buckets and a hose, it is very time consuming. If i did it all over i would drill my tanks and put in a drip system on a timer and the overflow would go out to waste i would still use the sponge filter i use now. I would use 1" bulkheads for my drains . the only issue's i see with using hose instead of pvc is cost and with hose you have to use pvc to hose adapters on the bulkheads i would go all pvc. I'm not sure what size hole you would drill for a 1" bulkhead but I do know it is bigger than 1" i would buy the bulkheads before i drill.


----------



## DJRansome (Oct 29, 2005)

See, it's not really a fish room. :lol: We are actually just remodeling the office. :roll: Every office needs a fish tank in the lobby, right. 

The whole project is on paper. An extraneous door has been removed, wall patched. Spackle and paint are needed. Decided to tile the floor. "Room junk" dispatched, etc.

I have an electrician and carpenter among family and friends. The electrician does plumbing and the carpenter does tile. That's a BIG help.

Yes I will do pictures.

There will be four 48" tanks (48x12x13). Two tanks high and two tanks wide. The two sumps don't count, right?

I have all these miscellaneous, utility tanks stuck here and there. The plan is always to get rid of them (sell this, grow out that) but they never seem to go away. So I'm dealing with reality and consolidating them in one easy-to-maintain place. The show tanks will stay where they are.


----------



## fmueller (Jan 11, 2004)

Most automatic water change systems just ad new water that will replace old water in the tank. That's only marginally less efficient than draining the tank first and then adding new water, but much easier to set up.

Assuming that's what you are planning on, what kind of drain you need depends very much on how the water goes in. Some people use a timer and a nozzle from an irrigation system to control how much water is exchanged. Since a comparatively large amount water is added in a short period of time, such a system needs a good sized drain. A large siphon overflow box might be able to cope, but everybody I know who uses such a system also uses drilled tanks.

An alternative is a drip system where water is added continuously in a very small amount. Since in any given time period only a minute quantity of water is added, you can get away with a very small overflow. A siphon overflow from 3/4" PVC pipe will be perfectly capable of doing the job. The only drawback of a drip system is that the control over the amount of water that is exchanged is not as precise as in a timer/irrigation nozzle system. In practice that hardly matters, and is far outweighed by the much lower cost of such as system, as well as the fact that you really don't need a drilled tank.









_Siphon overflow from 3/4" PVC Pipe for Drip Automatic Water Change System._

I am using such as system on my 125G tank that is not setup in a fish room, has no sump, and is not anywhere near a water supply or drain. For details how I set this up visit this page.

If you do have a sump, the overflow for the water change system will go on the sump, not the tank. If you don't want to drill the sump, you could use the same siphon overflow on the sump that I used on my 125G. My 240G has a sump made from cheap Sterilite totes that were easy to drill. That made for a very easy set up of that automatic water change system.


----------



## DJRansome (Oct 29, 2005)

For the four tanks in question, I'm thinking water in via timer, run the water for however long it takes to do 10% daily. The rising water comes above the bulkhead in the drilled tank and drains via gravity to the sump. The sump is also drilled and so again, rising water comes above the bulkhead and drains via gravity to outside.


----------



## fmueller (Jan 11, 2004)

How much is the timer going to cost you? Would you be interested if I had a solution that costs about $5, and does the same thing?


----------



## DJRansome (Oct 29, 2005)

No idea. Of course...tell! And I need to order the tanks. So...what more do I need to know or ask to size the drill holes?


----------



## TJL (May 23, 2011)

DJRansome said:


> For the four tanks in question, I'm thinking water in via timer, run the water for however long it takes to do 10% daily. The rising water comes above the bulkhead in the drilled tank and drains via gravity to the sump. The sump is also drilled and so again, rising water comes above the bulkhead and drains via gravity to outside.


 :thumb: i think thats the way to go


----------



## DJRansome (Oct 29, 2005)

Tile is arriving Tuesday, installation will be completed by Friday. :dancing:

How can so much junk accumulate in one 14 foot square room?

Gotta order the tanks.


----------



## DJRansome (Oct 29, 2005)

It seems like a 1" bulkhead with a 1.75" hole is a popular option. Any reason I should not go with that?


----------



## fmueller (Jan 11, 2004)

If you go with a drip system, there is no need to drill the tanks, but you seem fairly determined to go the timer/drilling route. I am not sponsored by the folks who sells $5 self drilling saddle valves via Lowes and Home Depot, which are the alternative to a timer I am using. So, I'll stop using the hard-sale approach on you 

For a system with a timer, a 1" bulkhead seems reasonable.


----------



## DJRansome (Oct 29, 2005)

The problem with a drip is I don't want to run the well for long periods. I did read the stuff on your website fmueller and saw the saddle valves.

Regardless of how the water get's in, it still has to be able to drain out, right? Isn't a drilled tank less risky than an overflow? Almost everything I read said the drilled tank is ideal, but you can make due with an overflow.

Give me the hard sell...maybe I'm still missing something. Happens all the time. :thumb:

I get that the overflow can remove enough water to keep up with the drip. You have an overflow on the tank and an overflow on the sump, right?

PS I was planning to use an overflow on the upstairs show tanks, but then I was thinking water would flow into a sump which would be drilled.


----------



## fmueller (Jan 11, 2004)

DJRansome said:


> The problem with a drip is I don't want to run the well for long periods.


I have never been on well water, so there might be something I am missing. Do you have to turn on a well pump before you have access to water? How about if you need to use the toilet real quick? Personally, I need to go several times during the night. Maybe I should better watch out that I never move to a house on well water :lol:



DJRansome said:


> Isn't a drilled tank less risky than an overflow? Almost everything I read said the drilled tank is ideal, but you can make due with an overflow.


That's absolutely true for a sump system. I have two Danner MagDrive 18 pumps running on my 240G, making for a flow of about 3,600 gph. I wouldn't want to run that through a siphon overflow! BUT with a drip system where the water just drips in, it will also just drip out. It makes no difference safety-wise if the water drips through a drilled overflow or a siphon overflow.

Also, if anything goes wrong, it will happen at a dripping speed. In case of my 240G that's still 30G in 24h, but for my 125G it's only about 12G in 24h. If anything goes wrong, there is a good chance you'll notice a small puddle on the floor after a few hours, and you can take care of it. If your timer malfunctions, and leaves the tap open for a few hours instead of a few minutes, there is more than a small puddle to mop up!

Apart from the inherent damage control through minimal flow, there just isn't as much that can go wrong with a drip system, since there are no electronics involved. Pretty much the only thing that can go wrong with a $5 saddle valve is that it blocks up over time due to limestone deposits if you have hard water. In that case the drip will slow down and you'll have no water change happening. You'll eventually notice that because the water level will sink due to evaporation. You can then repair or replace the valve, but there would be no flood or other major disaster. It hasn't happened to me yet, but that's basically the worst case scenario. With a timer based system, I reckon the worst case scenario would be the timer getting stuck in the open position while you are on vacation... 



DJRansome said:


> I get that the overflow can remove enough water to keep up with the drip. You have an overflow on the tank and an overflow on the sump, right?


If you have a sump, you need an overflow on the tank for filtration. That overflow should be able to cope with the flow of the pump you are using for filtration. The bigger the overflow the better. I use 2" overflows for my 240G. Reef-ready tanks that are not custom made commonly use 1" overflows, and the internet is full of discussions how you can maximize the flow through these narrow overflows if you want to use a more powerful pump. If you have the chance to get 2" overflows, you'll never have to worry about these shenanigans.

For a water change system in a tank with a sump you also need an overflow on the sump. That overflow only has to cope with the flow of the water change system. That is, if you use a drip system the overflow can be very small. A 3/4" siphon overflow is plenty in my experience.

If you had no sump, you could still have an automatic water changer on a tank. In that case the overflow on the tank only has to cope with the flow of the water change system. Again, if you use a drip system the overflow can be very small, because it is not used for filtration, which might be taken care of by HOB and/or canister filters.


----------



## DJRansome (Oct 29, 2005)

OK, at least I understand both options.

The well pump runs on demand. There is not much extra capacity beyond a toilet flush (since you mentioned it) without running the well. We know this from experience with power outages. As with any gizmo, continuous on-off cycling is more wearing on the unit than the occasional longer burst. On the flip side, it is not designed to run continuously for long periods either. For example, having a lawn sprinkler system, although it can be done with a well, will shorten the life of the unit.

Thanks fmueller...now I have to compare gallons/toilet flush with gallons/water change. :lol:

I was planning on using sump tanks for water change (drain) only, but for all tanks. Your post has made me realize I can bypass them and go directly to the drain. But question...

Does a short, straight drop from tank-on-stand into sump beneath give you better gravity drainage? A stronger siphon?

Or would it be just as strong if the water went through a longer pipe with more twists and turns?


----------



## fmueller (Jan 11, 2004)

DJRansome said:


> Does a short, straight drop from tank-on-stand into sump beneath give you better gravity drainage? A stronger siphon? Or would it be just as strong if the water went through a longer pipe with more twists and turns?


OK, this is a little complex. Usually in a non-drilled system you want to have a siphon effect going in the part of the plumbing that brings the water over the back of the tank. However, you do not want to have a siphon going in the part of the plumbing that actually takes the water down to your sump or the drain. The main reason the overflow I have shown in the photo above looks more complicated than just a bend hose is that it needs to maintain the siphon on one end, and break it on the other.

In a drilled system that feeds water from a tank into a sump, you usually want to avoid a siphon from occurring. I have only one tank with a sump system, which is my 240G. For that tank I am using a Durso standpipe, which is a system that uses a submerged intake on the drainpipe for noise reduction, but avoids a siphon. It is a very safe and very quiet system. In a nutshell, it has a bend in the drainpipe that ensure the intake of the pipe is submerged. If the output of the pipe is submerged in the sump, any noise originating in the pipe (which is considerable!) will be muffled.

Another way to silence an overflow is to use a siphon drainpipe, and balance the siphon overflow with the pump via a valve that reduces the flow through the overflow. In my opinion using such a system without and additional non-siphon drainpipe is a flood waiting to happen, because it is bound to loose that balance at some stage. I can scarcely believe anybody would take such a risk. I guess if you have only a 1" bulkhead and a pump that delivers more than mere gravity can feed through the pipe, people might see no alternative.

To answer your question directly, gravity drainage depends mostly on the size of the bulkhead, and you don't want to be in a position where you have to rely on the siphon effect to push more water through your standpipe than could fit without siphon.

Once again, for a drip system all this is utterly irrelevant because the flow is so low.


----------



## Morpheen (Jul 21, 2010)

Sorry nothing to add to this thread other than to say that its nice to see that you have your site back up fmueller! :thumb:


----------



## DJRansome (Oct 29, 2005)

This idea is starting to grow on me. I could skip the sumps and the drilling.

I have a couple more days to think, the tile is delayed 2 days.


----------



## fmueller (Jan 11, 2004)

DJRansome said:


> This idea is starting to grow on me. I could skip the sumps and the drilling.


----------



## DJRansome (Oct 29, 2005)

I was kind of into the idea of a drilled tank and a bulk head though...sick right? Maybe I'll do one just for the heck of it. :lol:


----------

