Volcano club
- Thread starter tom obrecht
- Start date
saleencobra
Premium Member
I have been questioning the performance of my 1875 since I got it. Does any one have ideas on how to improve it? I wouldnt even know how to check how much air it is pulling since the alita is attached to it.
JRaquatics
New member
I think the smaller Volcanos (under 20gallons) need a venturi like the Reeflo skimmers in order to draw air. Or like Hans states: the only way to gain performance is to use an air pump to feed the venturi.
Hans states: "Well, I met up with Tom last week and put an airflow meter on his Volcano. Its an RMC with 1/2" fittings, so it will be the least restrictive of any airflow meter... so no error there. Not to mention, the results wouldnt be off by THIS MUCH:
The bubble density and flow in Tom's look very similar to that which gopack is getting in his, and Tom's has the new removable inserts for the venturi. This skimmer is getting 45-50 scfh... which is only 1270-1400lph of air. No wonder Tom's tank has been in a perpetual state of crashing since he removed the Deltec 902... the 902 was getting more air. As it is, Tom and Bill (gopack) have to have their waterlines so high in the neck that if they turn off the skimmers, the airline is too short and water comes out. They are also so touchy with the gate valve that they either cant get the skimmate up far enough, or the cup ends up overflowing.
Tom has been trying to get a hold of Scott via phone, email, etc... since we met last week, but no response... no support. So now I'm posting what I know.
It seems like the important 'missing link' here is that in order to get enough air on the Volcano, you need to use a linear air pump. It seems like all those who are proponents of them have Alita AL-40's driving the air into the dart. Those who have the ones that are not force fed might really want to look into it. For force feeding, you should remove the venturi and just use straight piping into the pump. You dont want to have any sort of restriction at the air inlet (venturi) because with that much air going into the pump, you might end up choking off the water flow too much... so letting the pump run as free as possible is the main idea. As it is, you can put a bleed valve in the air inlet and you have the gate valve on the pump's intake so you can adjust the air and water inlets to get things just right. Im sure that there may be some point where the bubbles passing through the pump will get too large, so restricting the water intake a little or bleeding off some of that air is a good idea. For those who dont have a linear air pump on your Volcano, you might consider the same. Alita's are everyone's first pick it seems since they are tried and true, and tend to be the quietest. Another brand though, if you arent so concerned about noise (not that they are bad, but they just arent as muffled) are the GAST pumps... which if you see the Alita's and GAST's side by side, you would swear they are the same pump. I have a feeling once you add the linear air pump to the Volcanoes, they will perform just fine.... the waterlines can drop in the neck so overflows arent a problem, and your tank's wont be in a perpetual crash. Tom's tank has brown/red fuzzy cyano-looking algae all over, and his organic levels have clearly spiked... he should have the air pump sometime next week (since he cant seem to even get a hold of Spazz to return this thing because its clearly not working, he's trying to make the best of it)."
hahnmeister
In Memoriam
Well, what model Alita do you have? Assuming you dont bleed any of it off, its most likely getting close to the maximum output from the pump. The air is still 't-ed' into the pump inlet, so it should be under very low pressure, if not a partial vacuum even without a vanturi. So the back pressure on the air pump should be next to nothing.
According to the Alita site, the AL-40 at 0 pressure should do something between 60 and 65 lpm, which is 3600-3900lph (127-138 scfh). EVEN IF, the air inlet was under full depth pressure (if the dart was turned off for example), a depth of 4' underwater only gives you a pressure difference of about 0.1195 bar from the surface (remember when using the calculator below that you have to subtract 1.0133 bar from the depth value you have because that is the atmospheric pressure at 0 feet).
If you look back on the Alita site then at what .1195 bar would get you, that is about 55lpm (3300lph). But this is a 'worst case' scenario. Due to the air inlet on the suction side of the pump and that it is t'ed in, it acts like a venturi still (just not good enough to run on its own, and just not enough to restrict the pump any), so you can bet you are getting something about 3500lph if not higher (less than 0.0597 bar, the pressure difference at 2' of depth, which if you look at the chart puts the AL 40 in the low 60's for lpm)... so 3600 is a realistic number.
http://www.gazza.co.nz/waterpressure.html
If your pump is having trouble with this and starts passing larger bubbles, you might want to restrict the waterflow a little first. This will prevent the air from passing through the pump too quickly and give it more 'blending' time. 3600lph should be no problem for a dart, but just in case, you could have a bleeder valve on the air pump line to let some extra off. Still, instead of this, you might also consider adding some 'blending power' to your needlewheel... a layer or two of enkamat mesh (held in with zip ties to the pinwheel disk) should enable the dart to be able to blend up much smaller bubbles without any significant modifications. Adding this 'blendability' will also increase the pump's water flow though too (more 'bite' in the water with the smaller bubbles), so you might find yourself restricting the water flow again.
As for a Laguna, you can run those external as well... just have to add an o-ring to the volute. Otherwise, under 4' of head pressure, I wouldnt put alot of stock into using it as a pump over the dart anyways, unless you can give it a much larger volute/impeller well (same could be said of the dart, but I just dont think its as easy). The Laguna is even more sensitive to back pressure, so putting it on a tall skimmer will kill its output even worse. If you force feed... you could use Sicce PSK's if you wanted.
According to the Alita site, the AL-40 at 0 pressure should do something between 60 and 65 lpm, which is 3600-3900lph (127-138 scfh). EVEN IF, the air inlet was under full depth pressure (if the dart was turned off for example), a depth of 4' underwater only gives you a pressure difference of about 0.1195 bar from the surface (remember when using the calculator below that you have to subtract 1.0133 bar from the depth value you have because that is the atmospheric pressure at 0 feet).
If you look back on the Alita site then at what .1195 bar would get you, that is about 55lpm (3300lph). But this is a 'worst case' scenario. Due to the air inlet on the suction side of the pump and that it is t'ed in, it acts like a venturi still (just not good enough to run on its own, and just not enough to restrict the pump any), so you can bet you are getting something about 3500lph if not higher (less than 0.0597 bar, the pressure difference at 2' of depth, which if you look at the chart puts the AL 40 in the low 60's for lpm)... so 3600 is a realistic number.
http://www.gazza.co.nz/waterpressure.html
If your pump is having trouble with this and starts passing larger bubbles, you might want to restrict the waterflow a little first. This will prevent the air from passing through the pump too quickly and give it more 'blending' time. 3600lph should be no problem for a dart, but just in case, you could have a bleeder valve on the air pump line to let some extra off. Still, instead of this, you might also consider adding some 'blending power' to your needlewheel... a layer or two of enkamat mesh (held in with zip ties to the pinwheel disk) should enable the dart to be able to blend up much smaller bubbles without any significant modifications. Adding this 'blendability' will also increase the pump's water flow though too (more 'bite' in the water with the smaller bubbles), so you might find yourself restricting the water flow again.
As for a Laguna, you can run those external as well... just have to add an o-ring to the volute. Otherwise, under 4' of head pressure, I wouldnt put alot of stock into using it as a pump over the dart anyways, unless you can give it a much larger volute/impeller well (same could be said of the dart, but I just dont think its as easy). The Laguna is even more sensitive to back pressure, so putting it on a tall skimmer will kill its output even worse. If you force feed... you could use Sicce PSK's if you wanted.
Mr James
Premium Member
I am not sure. I do not have one of those air meters, but may put it in the plans for the future. Not too many reefers around me, so I can't readily borrow one from someone else. If someone has one they want to lend me, I will return it when I get the readings.
Low...?? I will measure and get back with you. See here for additional pics and information... Link
No bubble diffuser plate, just wide open space. I thought about one, but wouldn't know how to install it or where. I do have access to CNC equipment and acrylic.
25.5" tall
12" diameter body
16x16" footprint
It was running rich (wet) so I turned one of the pumps off this morning and am getting good skimmate, just not as wet.
Personal I don't like bubble diffuser i think the kill the pump performance .... but if you will need to make one there is no problem . IMO wait till you see this toy perform with better pump and always you can add the bubble diffuser.
i saw the skimmer and i am sure that one laguna 2400 can be good for this toy. if you not rush wait my friend work right now on a custom volute for those pump i can't give a lot of detail here... but those volute build very well and also look better then other that i saw.... also he making for those pump Pin Wheel . if you want to wait i will PM to you some photo and detail when it will be ready... i also working right now on big con skimmer and i am going to mod the 2400 again . before you buy the pump i will send you mine with air flow meter and you can test it on the skimmer . At this way we can be sure if it's work good or not before you spend money on the pump.....if it will be not so good then 2 1500 will kick in this skimmer very well .
you need to wait about 2-3 week till i get my pump back and i will PM to you right way (if it will be sooner you will know) .
HTH
Mr James
Premium Member
I am not ready to do much at this point in time to be honest. It seems to be running fine just the way it is. I enjoy reading about other pumps and what they can do. I will probably pick up an air meter one of these days....
I am considering a move to Germany, which means if I can't ship it, I store it....My system will probably have to go into storage for a couple years...
I am considering a move to Germany, which means if I can't ship it, I store it....My system will probably have to go into storage for a couple years...
Very simple , the air tube to the valve on the air meter .....
as far as your pumps i don't believe they pull more then 12LPM each . i have small one the RMA22 that will be good enough to those OR pumps . give me day or 2 i need to put there new valve and send to me pm with your address i will mail it to you to test the pumps .
ostrow
It's Dr. Goodluck Himself
My mesh-modded Sicce's pull 24lpm each, on a 10" body that is 30" total height. They need to be started manually when they stop though. Easy to mod them to about 18lpm and they start on their own every time (this is how ATI does it on the bubblemaster).
You'd need a few of those, but only one Laguna 2400.
Michael, please email me your address as I lost it. Got something to send to you!
You'd need a few of those, but only one Laguna 2400.
Michael, please email me your address as I lost it. Got something to send to you!
hahnmeister
In Memoriam
Way to hijack a thread guys...lol. One thing to consider is that th one larger pump (Laguna) will have more pressure handling ability than three smaller pumps of the same power. I say 'power' because the potential between one pump and another is determined by the volute diameter/thickness/outlet/etc. But lets put it this way... if you have three 33 watt pumps that each can do 1000lph, and one 100 watt pump of equal efficiency that can do 3000lph, the single 3000lph pump will have better head handling than the three smaller pumps because of how pressure and flow are related.... so at 3' of height on a skimmer, the smaller 33 watt pumps might not pump any air at all, while the single 100 watt one might still get 1000lph (just a shot in the dark, dont quote me). So in general... if you have to pick between one large pump and multiple smaller ones... the one larger one is the better bet. The challenge is that then you have to figure out some method of turbulence reduction, because one large pump doesnt have as diffused an output as the three smaller. This is where bubble plates really come in. Height can be used as a natural turbulence diffuser as well (higher up in say, a 4'+ tall skimmer, things calm down because the water flow usually gets left down below), but height also increases the back-pressure on the pump, decreasing the airflow. This is really why bubble plates are better. They allow a 2' tall skimmer to have as calm (and as attractive looking) a column of bubbles as a skimmer that is say... 3' tall... maybe more, and decrease the back-pressure put on the pump.
Mavgi has cited that he thinks bubble plates decrease pump performance by putting back pressure on the pump. Well... if this is the case, then you need a larger bubble plate and/or more holes for flow. You could also use a taller bubble plate and 'recirculate' some of the water that the pump puts out back into the pump's intake. A good bubble plate should put minimal back pressure on the pump feeding it. You can look at it this way too... there will be some restriction that a bubble plate causes... it has to or else the bubbles would stagnate under the bubble plate... but this restriction can be made to be as minimal (negligable) as possible, and this amount of restriction should be easily made up for by the fact that the pumps now dont have to pump into as tall of a column of water >>> The minimal restriction that a well designed bubble plate might put on a pump is well made up for by the shorter height that a bubble plate skimmer is able to work with and still perform like a taller skimmer. In short, the bubble plate might cost you 50lph of air, but being 12" shorter will gain you 100lph or more.
As for the Volcanoes... if you are force feeding, its a mute point.
Mavgi has cited that he thinks bubble plates decrease pump performance by putting back pressure on the pump. Well... if this is the case, then you need a larger bubble plate and/or more holes for flow. You could also use a taller bubble plate and 'recirculate' some of the water that the pump puts out back into the pump's intake. A good bubble plate should put minimal back pressure on the pump feeding it. You can look at it this way too... there will be some restriction that a bubble plate causes... it has to or else the bubbles would stagnate under the bubble plate... but this restriction can be made to be as minimal (negligable) as possible, and this amount of restriction should be easily made up for by the fact that the pumps now dont have to pump into as tall of a column of water >>> The minimal restriction that a well designed bubble plate might put on a pump is well made up for by the shorter height that a bubble plate skimmer is able to work with and still perform like a taller skimmer. In short, the bubble plate might cost you 50lph of air, but being 12" shorter will gain you 100lph or more.
As for the Volcanoes... if you are force feeding, its a mute point.
hahnmeister
In Memoriam
All the talk about Lagunas and Sicces for a skimmer that isnt even a Volcano. Yes, Spazz made it, but its from before the 'Volcanoes' which so far have been ReefFlo powered. Otherwise, Bill Wann's 30" diameter 'mega skimmers' might be considered topical as well...lol. No big deal... just thinking that maybe a 'Volcano club' thread might deal more with Volcanoes... thats all.
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