Volcano club

[prostaff]

<a href=showthread.php?s=&postid=13505330#post13505330 target=_blank>Originally posted</a> by Herpervet
Interesting. How many stones /type/size are you using?

I have (4) 6in and (3) 3in Clearwater fine-pore ceramic airstones sold by Aquatic eco-systems in the skimmer.
They were only like $13.99 each and I have had them since feb 07. So that is really cheap considering I don't have to replace them every 4 weeks. Even better thing is that I didn't really notice a decrease in performance after the 8 months

 

[Reefaquariumnut]

If you have a good bioload you should have to let it run for 2 months...even 1 month sounds long. I would let i run a few days and see what happens. I your like your adjusting of the inlet fitting direction inside the skimmer. I think the best option is to try the mesh mod and reduce the air line input (smaller dia). Is there anyway you could make a longer neck without major modification? Seems like that could be a missing link too.

 

[Sparkss]

Reefaquariumnut

Thanks for the suggestions, but thre mesh mod is a no-go for the reasons I noted in my previous posts, namely that I run O3 and so far there isn't any O3 resistant mesh material (the stuff everyone uses is nylon.. *ugghh*). Also, I was chatting with a skimmer "expert" last night and he told me that he had not been impressed w/ the mesh mod results he had seen on dart NWs. This was a general statement about dart NWs and not about Volcanos, but that, coupled w/ the lack of adequate mesh media, was enough to dissuade me to even bothering w/ going that route.

I also don't 100% agree w/ the smaller diameter air line. All it serves to do is restrict the air flow, and that is accomplished by use of the ball valve installed on the air pipe of our volcano (which I have tinkered w/ to see what results I could get).

Jonathan

I went back to try to automate a feed timer (that I didn't need to go into the fish room to activate). I tried timing how long it took after a feeding for the skimmer to be able to run at "full speed" again. Although I only had 2 feedings to measure, the time seemed to vary greatly. I am just going to have to try to adjust things so that the feeding doesn't push the pump into cavitation *sigh*

Anyways, here are some observations, actions taken and future tuning plans :

After some tweaking I let it run overnight and this morning there was a full head of foam, all the way to the top of the neck. I almost hate to feed the fish today as I know it will destroy that progress *sigh*

Here is what I did last night :

1. I raised the water level to just below the twist lock. This actually changed the back pressure on the recirc pump and forced me to "tune" it again.

2. I lowered the O3 yet again down to approx 25 mg/hr (not sure if this had any effect or not)

3. I tuned the recirc back up to 130

Here is what I plan to do, maybe this weeekend :

I read through and it seems that I am pushing more water through our skimmer than anyone else. Even Volcano1 w/ the snapper feed pump is 50% less than we are moving through our skimmer (not to mention that we had to chop our skimmer so it is 10" shorter than his now). So I am going to "bleed" off a good portion of the overflow water directly to the sump, leaving about 1k gph going through the skimmer, just to see how it functions. Even though Scott said that it would work as we have it now, I just want to see if it will perform better w/ less flow through it. It won't be a big deal to test, more adjust, wait and watch, adjust again, etc. I already have a bypass drain in place for whenever I may need to take the skimmer completely offline but don't want to shut down the tank. So I just need to adjust the valve to that bypass and see what happens. I have hopes that it will cut down on the turbulence (of which there really isn't that much) and increase the bubble density (since the flow through water will be less it should take less bubbles to "fill it" ?). I guess I will find out this weekend what it buys me .

I also suspect that I have sheared some pins on our NW, but can't be sure. My skimmer is before he started putting the drains in the bottom front (like you see in the pictures on his web page, which is still up btw). So just checking the NW is a pain (which only means that it is not something to be done "lightly", or often, if it can be avoided). I tried to contact Scott about a replacement NW (even offerred to pay for it in the messages I left), so far I have not heard back from him. I may pick up a stock Reeflo NW (about my only other option at this point) to have on hand, and if our NW is damaged, swap it out w/ the Reeflo one and see how that performs.

 

[jnarowe]

My God man, I would hang myself.

I raised the water level to just below the twist lock.

That's pretty extreme right? What is your schedule like? Can you fly out for a couple 3 days? You could bring the skimmer and we could mod it big-time. Just get all the parts together here before you come out, and turn that thing into a very efficient air stone skimmer. Then you would never have to worry about any of the adjustment crap, damaged NWs, electrical draw, etc.

It's a shame to see you going through this.

 

[Sparkss]

Jonathan, I will give you a call and talk through some of this, I am starting to agree with you on several of those topics. What time works good for you ? (shoot me a PM or an Email ).

 

[jnarowe]

ON THE WAY.

 

[X men]

Would you not better try to modify the dart gold, with the special NW impeller that is created by Reefspecialty.com ? seems to be of good quality, and the price is low. If it works, than everything is fixed for +/- 75 dollars. If not, you can stil decide to modify the skimmer itself.

There is a good thread, by GlassReef (thread on building his 375 gallon glass reef) now in the Large Reef Tanks section of this forum. I think you should look at it, seems a good idea, for little effort and little money.

 

[Sparkss]

you can only get that NW if you buy the Reeflo skimmer + the Reef Specialty modified collection cup. I had a nice conversation w/ Mike from RS last night about it. If I could get one of his NWs, I would, but there are legitimate reasons why I can't, so unfortunately that is not an option for us. Thanks for the suggestion though, and for trying to help out .

 

[Nanook]

Not sure which "expert" poo-pooed the mesh mod but they are dead wrong. I speak from personal experience

If that were my skimmer I would drain it and install a drain for ease of maintenance in the future.

 

[hahnmeister]

I dont think anyone did... the fear was that the pump might be a 'high speed' motor (which it isnt, its a low speed one) and cause the mesh to fall apart.

I have seen mesh-modded darts... so I know it is possible. IMO they are no worse for wear than regular needlewheels. With larger chunks, needlewheels have less play so the larger chunks tend to get stuck in between the pins until cleaning.

With mesh, chunks like this might get stuck for a bit, but over time, the mesh stretches and balances itself out... so a small snail that gets trapped in it one day is often passed through the next.

As for small bits and thread/hair like pieces... well... either one has problems with that, but if nothing else, a piece of chaeto would ADD to the mesh on the impeller, acting like another 'thread' itself... so what's the big deal.

As far as the mesh breaking up... that takes time. A nice meshwheel shouldnt need to be redone more than once a year IMO. The nylon is very durable (unless exposed to ozone).

 

[Sparkss]

hahn, nanook was referring to my comment that I had spoken to someone w/ experience with the dart NWs in general (mostly on Reeflo skimmers) and they had told me that they weren't impressed w/ the results of the mesh mods.

and yes, nanook, each time I drain it I say I am going to install a drain for future ease, but each time I forget to order the uniseal and fittings to do it. If I do go ahead and drain it to check the NW this weekend, I will again have done so w/o the proper parts to install a drain (at least I am consistent).

I am still on the fence about just modding it and dropping in a bunch of air stones. I mean the main purpose for the NW is to introduce air into the water column (preferrably in the form of small tiny bubbles), right ? the recirc doesn't actually serve to recirculate the dirty water from the tank any more or less than the "clean" water trying to exit the skimmer. So why not use an airstone array ? Seems like the power consumption would be less also. The Alita 100 runs @ around 120 W (according to the Alita site), our recirc pump alone runs @ 130 right now, plus the ~46 for the Alita 40 (ok, so not even $20 per month savings there, but here in Ca every penny counts when it comes to utilities bills.. plus if it works as good or better, then the savings is just a bonus, right ?)

 

[jnarowe]

My Alita 100 is running at 105W.

 

[hahnmeister]

An easy mod for the airstones that doesn't involve drilling the base, the cylinder, etc would be to drill the center of the cover and run a 1/2" pipe straight down the center to the bubble plate (and go into it, or perhaps just sit above it... I dont see any reason for the bubbles to be injected below the plate... they dont have water turbulence). You could have the airstones spread out in an 8 point star pattern. When you want to remove them... just lift them out of the top. If you want to remove the cup w/o the stones, just put a union on the pipe, or better yet, just use a uni-seal and cut the pipe on the top side of the cup... when you want to remove the lid, just undo the hose going into the pipe, and pull the pipe through the bottom.

If you do want to feed tha array of stones from the side/bottom area, you dont need to add a whole 'trap door'. You can just use a single uni-seal to pipe it in from the side. Then have a union on the pipe on the inside, and a ball-valve on the outside. When you want to remove the stones, you can just turn off the air pump, reach down the neck to undo the union on the inside, and lift the airstone array out through the top. The valve on the outside allows you to turn off the pump and not have water come out... then again, chances are your air hose/pump will be high enough to not need this anyways.

So really, its about a 10 minute mod with some PVC and a uni-seal. The tricky part might be to add another hole to pump the air in under the bubble plate. I dont see a huge advantage to this in itself (and the question still begs to be asked... if the mixing pump is still there, why aren't you pumping as much as possible into it before adding stones... otherwise the needlewheel is just a total loss, no?)

 

[prostaff]

<a href=showthread.php?s=&postid=13516528#post13516528 target=_blank>Originally posted</a> by Sparkss
hahn, nanook was referring to my comment that I had spoken to someone w/ experience with the dart NWs in general (mostly on Reeflo skimmers) and they had told me that they weren't impressed w/ the results of the mesh mods.

and yes, nanook, each time I drain it I say I am going to install a drain for future ease, but each time I forget to order the uniseal and fittings to do it. If I do go ahead and drain it to check the NW this weekend, I will again have done so w/o the proper parts to install a drain (at least I am consistent).

I am still on the fence about just modding it and dropping in a bunch of air stones. I mean the main purpose for the NW is to introduce air into the water column (preferrably in the form of small tiny bubbles), right ? the recirc doesn't actually serve to recirculate the dirty water from the tank any more or less than the "clean" water trying to exit the skimmer. So why not use an airstone array ? Seems like the power consumption would be less also. The Alita 100 runs @ around 120 W (according to the Alita site), our recirc pump alone runs @ 130 right now, plus the ~46 for the Alita 40 (ok, so not even $20 per month savings there, but here in Ca every penny counts when it comes to utilities bills.. plus if it works as good or better, then the savings is just a bonus, right ?)

I agree with calling Jonathan and doing the airstone mod. I figure it will only cost me like $75 in airstones and 1/2in pvc or hose.
I did my airstone skimmer by tapping in a 3/4 in hole near the top of the body. I then put a 3/4 male thread to slip connector that allowed just enough thread on the inside of the body to conect 3/4in pvc pipe via union (for easy removal/cleaning) to a 6 way circular manifold (sold at the same place for $30). Since you already have an alita pump available to you you can try that and compare and if you don't like it it will only cost you one plugable 3/4in hole and $35( Since I will gladly buy the stones from you for 1/2price )
I am definitely going that route with mine. I really like the idea of being able to control water and air seperately. If I don't like the result which is highly unlikely, I can use the new 3/4 in hole as a calcium reactor effluent input. Always wanted to feed my skimmer with that anyway and now that I don't have to worry about what the calcium may do to my recirc pump....

 

[prostaff]

<a href=showthread.php?s=&postid=13516810#post13516810 target=_blank>Originally posted</a> by hahnmeister
An easy mod for the airstones that doesn't involve drilling the base, the cylinder, etc would be to drill the center of the cover and run a 1/2" pipe straight down the center to the bubble plate (and go into it, or perhaps just sit above it... I dont see any reason for the bubbles to be injected below the plate... they dont have water turbulence). You could have the airstones spread out in an 8 point star pattern. When you want to remove them... just lift them out of the top. If you want to remove the cup w/o the stones, just put a union on the pipe, or better yet, just use a uni-seal and cut the pipe on the top side of the cup... when you want to remove the lid, just undo the hose going into the pipe, and pull the pipe through the bottom.

If you do want to feed tha array of stones from the side/bottom area, you dont need to add a whole 'trap door'. You can just use a single uni-seal to pipe it in from the side. Then have a union on the pipe on the inside, and a ball-valve on the outside. When you want to remove the stones, you can just turn off the air pump, reach down the neck to undo the union on the inside, and lift the airstone array out through the top. The valve on the outside allows you to turn off the pump and not have water come out... then again, chances are your air hose/pump will be high enough to not need this anyways.

So really, its about a 10 minute mod with some PVC and a uni-seal. The tricky part might be to add another hole to pump the air in under the bubble plate. I dont see a huge advantage to this in itself (and the question still begs to be asked... if the mixing pump is still there, why aren't you pumping as much as possible into it before adding stones... otherwise the needlewheel is just a total loss, no?)

That's funny Hahn. I guess we were typing at the same time. I drilled mine through the side because I didn't want to have the pipe in the way every time I went to clean the neck of the skimmer but I guess if one wanted to experiment first that would be one way to check before going to the final step. Heck you could just leave the cover off, stick a pvc pipe with a manifold in, letting it simply sit on the bubble plate and just see how it runs before doing any drilling at all

 

[jnarowe]

I am not convincd that an Alita 40 or 60 will produce enough air to make this work. I really feel it needs more air. In theory, the recirc is supposed to recirculate water and air, thereby increasing the amount of air within a longer contact time.

Having the pipe go down the center does not seem to be a good idea IMO just because there would be significant extra surface tension to overcome. As I said to Tom, one hole in the side is no big deal. It can always be plugged.

The real issue is getting enough stones (and air) to make the Volcano what it should be. Tom and I spoke for quite a while and a couple interesting things came up. One is that when he shuts down the air pump, the wattage on the Sequence pump goes well beyond what it is rated for. This is cause for concern and possibly shows either a problem impeller, a possible blockage, or some sort of back pressure.

And I feel based on all that I have read and discussed, that there is some sort of back pressure within his skimmer. I find it hard to believe that an Alita 40 could cause the NW to cavitate just because he feeds. I just don't feel that should happen. Having to stop the air pump and restart it to quell the cavitation seems to show some sign of backpressue IME.

Perhaps it could be accounted for by understanding whether there is just too must water volume (height) above the air pump? This could be tested by running the air pump off a Kill-A-Watt and comparing it to spec. For instance, my Alita 100 ran right at 120W (spec) with a long and undersized tubing and the 4' water column. When I switched to an extremely short over-sized tube and installed giant airstones with 4 x the surface area, the Alita now runs at 105W.

So many variables, so little time!

 

[Sparkss]

I am working on getting my hands on a stock Reeflo/Dart NW. I hope to have it next week sometime. At that time I plan to take and skimmer down, clean and inspect the design to see if I overlooked anything, or put it together incorrectly somehow. If not for waiting on that NW I would take it apart this weekend to see if something is lodged in, or otherwise impacting the NW and maybe causing the high wattage draw when I shut off the air.

I am baffled by the high wattage draw as well as the cavitation when we feed the fish. Neither one make sense to me, but maybe I am just overlooking something obvious. I know that the oils in the food reduce the surface tension and can shut down the skimmer in so far as it producing skimmate, but I have never had one fall over into caviation from it. And when it goes over the edge to cavitation it will never come back to proper pumping until I shut off and restart the air pump (at least 1 - 3 hours after the feeding). I also don't see where the back pressure, or whatever is causing the high wattage on the recirc pump when the air is turned off. I cna only assume some sort of blockage and/or impellor/NW issues (unbalanced from lost pins maybe ?).

To date I have also investigated the possibility of a too restrictive collection cup/lid. I even went so far as to prop the lid open on the top of the cup to see if there was not enough air holes in the lid to let all of the air out. I had been thinking about this for a day or so, and talking to Jonathan and having him bring it up also made me add it to my list of "things to try".

Hahn, if I went the air stone route I would not use the recirc at all.

And I believe Volcano1 spoke about two dif NWs from Scott, one w/ 48 pins and one w/ 100+. Ours is the 48 pin model, IIRC. From memory, it didn't look anywhere near 100 pins, but I won't be sure until I open her up to replace the NW when the new Dart NW arrives.

 

[JCTewks]

The pumps wattage is going up because when you shut the air pump off, the pump is then moving the same "volume", only the bulk of the air that was being pumped is now water being moved. It taes more energy to move the water than it does to move the air/water slurry that is going in with the air pump on.

It is the same as if ANYONE who has a NW skimmer would plug the airline while the pump was running...the wattage would increase dramatically...although most of that increase is in RMS wattage (V * A * PF =RMS watts). when running a mixture of air/water through the pump the PF drops, and that is where MOST of the noticeable watt decrease is from.

 

[jnarowe]

Understandable of course, but why would it go well beyond spec? Shouldn't it be at spec. with 100% water and less than spec. with an air/water mixture?

 

[JCTewks]

Well, it depends Jonathan!

It "should" be at spec with only water...but that's only if the new PW has the same mass and drag as the stock impeller (which it does not)

PW's are designed to move water AND air, not just water...so testing is usually not done with water alone to see what the watts are. I once burnt up a pump because I had the airline running into my collection jug, the skimmer went nuts after epoxy ony day (after I left for work of course ) and the airline started drawing water instead of air and the pump burnt up from pulling too much elec.