thnks for the pm- nice work. good graphics.. gona have to think about this.. :-)

there is one problem with the daisy chaining DIY air pressure cans.. as i did a similar feat with a bunch of old 1/2 gallon jugs..

any jug downstream from the air .. if there is ANY small leaking in the seals.. you will loose that air space on the top until the upstream ones empty out. this will turn into a slow leak... not too important.. slow leak- just be carefully.

remember - it is wise to have an air release valve someplace in the system too. to remove the pressure that causes leaks like this is multi jug systems... some air pumps will act this way if they don't have check valves...

Oh, I see. That is a good point. Well, in the past, I have used just a single jug with kalk being mixed in and it worked...I know it isnt a true reactor...but hey...were talkin nano here anyways...

Well i am almost complete with the process of making one of these. I have two questions,

1) I dont have space for a pvc pipe like in your plans, how would you suggest I put the float switch on my tank(eclipse 6).

2) is there any way to quiet this thing down, if not I may just have to do my topoff on the day timer with the lights. I know that this may create larger swings at night but most of the evaporation will occur during the day when the lights and fans are on anyway.

Thanks for the help.

If you dont have space for the PVC, perhaps a piece of plexi bent with a hole in one part for the switch would be good. There are many possible ways to do this, many of them explored in other threads already. The only way I could make a specific suggestion would be if you had a picture. Now, as far as the noise...yes, it can make some...and running it on the light timer is a fine idea...like you said, most of it happens during the day when the lights are on...and although that may not make it 100% stable...it is still loads better than doing it by hand. I use about a gallon a week on my ten gallon, and my salinity does not flux anything noticable throughout the day. It is so gradual, I just forgot to turn it back on yesterday after doing those tests...my water level dropped and I was scared cuz I tend to keep my salinity at the upper end...1.025%...but I checked it and it was still 1.025%...no big deal. If it was, Im sure my brittle stars (notorious for being sensitive to salinity changes) would let me know.

radar.. i would test it under pressure for a few days. every few months..... you can use check valves to keep the pressure in pump it up... and let it sit.. if that air space is there in a few days- you will be fine... just make sure your opening and filling the kalk doesn't make it loose- most jugs do not have o rings... and as plastic wears.. it looses the seal... [unless you find one with an O ring :-) and can definatly secure the hoses airtight


remember that tank- due to the upstream pressure of the water- is going to remain under some pressure all the time....

my only worry is if loosing air- especially out of the kalk side.. will spill kalk all around... and that can be a mess...

Question, is it necessary to use rigid line in the water container? I'm working on my battery powered auto top off and I can't get enough pressure to pump the water up approx. 4 ft to drip into my HOB skimmer.

I can't start adding my corals to it until the auto topoff issue is handled cuz i get a lot of evap(pc fans needed for temp control)

hey will this battery air pump work?

http://www.drsfostersmith.com/product/prod...ial&Np=1&N=2004

another question I have is do you add kalk to your top off water? I would like to (for my 44g) and incorporate this auto-top off so I was wondering if it I just have to set the float switch level up high so it frequently adds small amounts to my tank? thanks

billpa

I too have a question. I really like this idea, but my understanding is, and someone please sincerely correct me if I'm wrong, but the ph goes up when the lights come on, right?

And when the lights are on, is that not when you experience the most evaporation? I'm totally guessing there but it seems logical.

And if so, is that the best time to be adding kalk, which increases the ph even more?

And if that's true, wouldn't that mean the the ph is really high while the lights are on, water is evaporating, and the kalk is being dosed, and then drops really low when the lights go out?

I'm looking for an auto-topoff solution, but I only want it to come on after the lights go out, to sort of balance out the ph. Hey I just thought of something. I guess you could put the phone charger adapter for this auto-top offer on a timer opposite the lights, eh?

yup...just set up a timer so you just top off at night.

You are right. This is the reason why many run both a kalk reactor and calcium reactor (aragonite based). Or, if they run kalk alone, they run the kalk off of a seperate drip (24/7), and the top off with just regular water. You have pointed out a problem some might be concerned with. I dont use a kalk reactor, so I cant comment any further.

Hmmm. The only problem is that it will probably dump it all in there at once right after the lights go out.

Is there a way to have the pump come on after the lights go out, but just long enough to start a syphon through a slow drip valve, and then somehow break the syphon and stop the slow-drip when the float switch detects the water level is good?

Is this taking it too far, or does this issue actually have some merit?

The syphon thingy...no, no way to do that that I can imagine.

Perhaps you should ask birdman in the advanced forums about the merits of timing with regards to autotopoffs and kalk.

Yea, but reactors are EXPENSIVE! That's why I'm trying to get around it with something like this. One day when I have a 500 gallon tank, I'll buy a reactor!

10-4 on the birdman.

Very cool project.

Since I'm a newbie on the reef stuff, maybe I can contribute on the electrical stuff...

First, it looks like the battery discussion has parallel and series reversed. Two 1.5V cells in series will be 3V, and 1.5V in parallel. Not that what you call it matters as long as the adapter voltage replaces what is actually measured.

Also, most switches can cary much higher AC voltages than DC. Flipping open a Jameco catelog, and looking at a random relay, it can handle 3A, with either 250VAC or 30VDC. DC is much harder on switches, because when the switch is flipped, a rush of current (starting or stopping) tends to arc the gap, wearing out the contacts. AC has multiple zero crossings per second, giving the switch a smaller voltage/current it has to break. People often think if a switch can handle 2A at 120VAC, it can easily handle that amperage with ~13VDC in automotive applications, such as extra lights, but this is not the case. If the switch isn't rated for that DC load, it will wear out very quickly.

At least this is what I remember from my engineering degree, long long ago.

I agree that having one fewer sources of 120V in the tank is a good thing though.

-Michael

I think I just thought of something.

What if you have two of these? One of them could drip RO water during the day and the other one could drip kalk at night?

You can just put the pumps on timers. That way, the water level would stay at a reasonable level all day, so you would never be adding too much at once.

BTW, thanks for the feedback Undertheradar!

Wolf

thats not a bad idea Wolf...a larger container would probably be in order for the daytime RO topoff...and then all you would need is a small container for night time...although I dont know how much evaporation you will get after topping off in the daytime continuously...I'm sure you could restrict the flow a bit so that you could do kalk top-offs 24/7...or at mount the float switch up high so that it is activated more often and lesser volume top offs...what do you think Undertheradar? and I forgot to ask you if you buffer any of that automatic topoff water.

billpa

Actually, I'm pretty lazy so I was thinking of two 55 gallon drums.

j/k

haha...thats funny...actually I just snagged a water jug from the office water cooler and will be using it for my auto top off unit...now I just have to go out and get the pump

UTR is the man when it comes to DYI, especially plumbing . listen to him.

Bill, make sure the pump you get is small enough to fit through the hole in the reservoir ....

I was going to do an air powered ATO as opposed to a submerged pump

I was just reading this article and from what I'm gathering from it, the limewater will lose its potency in a reservoir if it's continually mixed or not sealed well, something to do with the mixing of of carbon dioxide in the air, I think.

http://reefkeeping.com/issues/2003-05/rhf/...ature/index.htm

The author, Randy Holmes-Farley, suggests mixing the kalk with the water initially, and then letting it remain still during the dosing process, making sure that the lid is tightly sealed. He also claims basically that this method is actually better than a kalk reactor!

Just thought it might be some useful 411 to someone...

BTW, I just ordered my floatswitches. I can't wait to put this into action!

Wolf

My auto top off is finally finished thanks to your plans. I spent forever looking for the right jar and I found it. Its an applesauce jar that is thick plastic and a great sealing lid. Now I just have to figure out how and where to mount the switch in my tank

heres the new and improved bracket system I am using. It is a piece of 1/8" acrylic bent into a narow 'Z'. This allows the pump to hang on the side of just about any tank. Then I drilled a 3/4" hole on the bottom. The pump hangs on this from it's clip...down and out of sight. The top part of the acrylic gets two 1/8" holes for the bolts that hold the PVC pipe strap and what not. I had to make this for someone because they were going to mount the top-off on the main tank, but the clip on the air-pump only has a 1/4" clip... The float on this one also would have to be mounted higher than the sump mount model. This bracket allows the pipe to be adjusted higher than the old version.

I think I will start making these buggers for $25 + shipping. I had to go up from $20 because after I run out of the bulk buy float switches I will have to buy the $5 ones. Oh, and the cap I include is for/from the one gallon gatorade jugs...$5 a jug, but hey, it's summer so I can use the gatorade...LOL.

oh, and the pic:

the pipe also has two small holes in it now...one in the top for the water feed line to mount in more securely...and one above the float to allow fresh water to spill out right above the float after it goes through the pipe. My hope is that this will knock off any critters that might trip the float in the tank with a dose of fresh water. My snails fall off when I spray fresh water at them... Of course making a guard out of a pill container would be good too.

from the back...

I just finished making my top off. I used a battery air pump, and a 32oz wide mouth Nalgine as the container. I have not mounted it yet but in playing with it I notices that a siphon was easily created and not easily broken. Any ideas on how to minimize the chance of this happening before I mount it? Let me know

Jerome

the water supply should be mounted below the outlet, and the outlet mounted above the water line.

Just as idea, for those of you who are trying to use this topoff for freshwater topoff as well as dosing, I have an idea which might work...

Keep the 2 containers as previously discussed, but rather than running them in series, run them in parallel. What I mean is that you can put a tee on the airline going to the bottles and pressure both at the same time. The tricky part is trying to dose a smaller amount than the makeup. To achieve this, you can put the 2 bottles at different elevations. The pump will supply the same pressure to both, so the required difference in elevation (from the makeup/dose water level to the tank level) will cause a different flowrate for the 2 bottles.

It will take some trial and error to get the elevations correct, but I think that this may be an option, rather than the timer and just dosing at night. Since I am a noob at this, I do not know if dosing 24/7 is better than only at night.

Hope this helps, and great job on this design UTR, I should be ordering my parts this weekend. If this does not make sense for some reason, please let me know and I will see if I have any other ideas.

Bryan

I just dump the stuff that I want to dose into the top-off water itself. The only exception is a kalk reactor top-off, but that requires a whole other set of rules. I have never seen a reason to go to this extreme in a nano however. I mean, dosing a 2 part calcium system on such a small tank has really never been a problem....then again, I have seen my share of nano-reactors.....

Hey! I just built one of these based on your original post. It works great and was really easy! Of course, it's only been in there for five minutes, so we'll see. I'm going on vacation in two weeks and needed to come up with something. Anyway, thanks for the info!

Are you taking orders yet?

Carl

Are you-since their are no patent laws to get around this time!

Sam

If you are using a Nokia cell phone charger, realize:

1. The wattage that the airpump draws should be less than the wattage the cell phone charger is rated for.

2. The greater the difference in wattages, the greater the voltage you are feeding to the air pump. Since I'd be willing to bet dollars to donuts that these little chargers are unregulated, that means that a 500mW charger driving a 50mA airpump is NOT going to deliver 3.6v. It's probably going to send 5v or more. So grab your voltmeter and check it while the pump is running. You may be slowly frying your pump with excessive voltage!

Since I'm posting anyway, let me voice my opinion on the floatswitches.net switches: they are completely safe at 110VAC with low current (wattage) usage. That said, DC is safer for humans when water is involved.

I really like the auto top off idea. It is a great concept. The idea of using an air pump for a dosing pump is not such a good idea. It will work, but the diaphram in the air pump will wear out quickly. Any time you greatly throttle down a diaphram air pump it causes severe stress to the diaphram.

I don't get this statement. How is pushing air into a bottle with RO/DI water any different than pushing air into a bottle with RO/DI & limewater mix?

I made one of these by the way, and I love it! It's impressed a lot of the guys I work with too. My only beef is that it's setting right next to me on my desk at work, so my heart skips a beat every time it fires up. Between that and the bacon double cheese burger diet I'm on, I don't think I'll make it to my next birthday.

Has anyone tried using a similar air pump, but a more quiet one?

"Any time you greatly throttle down a diaphram air pump it causes severe stress to the diaphram."

FYI, crack one of the DC versions open and you will see that they are not diaphram pumps. They are piston driven (works better w/ DC). I have been running the battery one for about 6 months now and it hasent skipped a beat. You might assume that 'all that back pressure' is bad...HUH? Thats what they are designed for in the first place (remember pumping airstones underwater aint easy either)! Operation as an ATO is a cakewalk for these pumps compared to providing constant air to a portable container with who only knows how much back pressure because of whatever depth and airstone. The minute or two that these are on a day is very little wear&tear all things considered. I have even rigged up another with the nokia 3.3v charger. It sounds much louder, but works great. Often in DC devices, they are using parts with tolerances much higher than the specs. Why? Cuz rather than make a new pump every time, they raid the parts bins and see which supplier can provide a good pump...sometimes the ratings are 3x or more what they normally run just because they were the readily available part and still compatible. So far Im on month 3 with the nokia version...well see. A few bursts a day, even at a slight overpowering, is not alot of wear. Keep in mind were talking 30 second bursts or so...not alot of time to build up wear&tear, heat, friction, etc.

"1. The wattage that the airpump draws should be less than the wattage the cell phone charger is rated for."

Sure you dont mean the other way around? I mean, wouldnt you rather have a 2v charger on this rather than a 5v?

I was speaking of wattage, not voltage. If you have a 50mW charger trying to supply a 100mW load, your voltage will drop and things will overheat. With most solid state electronics, too low of a voltage is no problem, things just don't work. However, low voltages can harm motors when there's not enough field strength to spin things up. That's why variable speed motors use Pulse Width Modulation, not variable voltage. But now I'm rambling... sorry.

[QUOTE]Originally posted by Wolf
[B]I don't get this statement. How is pushing air into a bottle with RO/DI water any different than pushing air into a bottle with RO/DI & limewater mix?

The auto topoff may run a couple minutes a day depending on tank size. The doser will run constantly. If this a piston pump it will hold up better, but don't count on it's longevity. I would keep a spare pump on hand. As for the auto top off it will work great because it isn't on long enough to accumulate damage to the sealing surfaces.

Roger that. The two-part ATO/Doser that I was referring to earlier in the thread would run the two different pumps in synch with the lights, so the ATO with RO/DI would be on during the day, and the ATO with the kalk would be on at night, when the PH is low. Although, as UnderTheRadar pointed out, these pumps don't have diaphrams.

And in retrospect, I think such a system would be overkill for a nano with a clownfish and a few soft corals.

Now for the love of God, would somebody please help me come up with a way to quiet this thing down? Otherwise, I'll have to add Depends to my aquarium budget.

you could give it some back pressure to slow it down, and in the process, quiet it a little. Otherwise, making a little sound box with padding might be your best option.

Is there a way I could mod this for use on a nano cube that has the overflow mod. the back section varies with evap, so I could somehow get the float back there.

"Now for the love of God, would somebody please help me come up with a way to quiet this thing down? Otherwise, I'll have to add Depends to my aquarium budget."

Penn-Plax makes a model similiar to this that they call the Silent Air. I found it at Pet solutions.

i'm interested in trmiv's question (even though i dont have the overflow mod). how would this fit in an nano cube? would i need to cut a section out of my hood, or would is sit low enough where i wouldnt need to? undertheradar, i want to buy one of these things from you, are you still taking orders?

I have one built, but the design is a bit different than UTR's. The unit cannot extend as high on a NanoCube without cutting a section of the hood off. The way that I have done it is to have the float switches mounted below the edge of the tank instead of above it as UTR hs done. This is probably not a major problem, assuming you do not mind running the level of the rear compartment about 3-4 inches below the overflow. You will still need to cut a small gap in the back of the hood so that the support will fit, but there will not be any obvious mods unless you look at it from the back.

As I said, mine is built, but I have not had a chance to install it in the cube yet. That will hopefully happen this week some time. If my explanation is not adequate, please let me know and I will try to sketch this up for you to see what it looks like.

Bryan

yeah, i guess that wouldnt really work for me because i havnt done the overflow thing and i dont really know how i could with all the stuff in my tank. maybe i'll just have to cut up the hood some