Fully Self Cleaning Skimmer Cup/Neck with Enhanced Dome Lid

[CuzzA]

Ok, so as I looked at the design of nearly every skimmer, I see many flaws. Of course these are probably more "cost" associated than anything else.

The one major flaw I see is the design of the flat lid. Logic tells us that the reason why the skimmer lid is always loaded with gunk is because that's where the bubbles are popping. How many of these bubbles are actually popping and falling back into the neck? I don't know and I'm not going to watch a slow frame video and try to count bubble bursts.

Nevertheless, I did decide to add a dome to my lid. My logic behind this is that I'll increase skimmate production and efficency because A) The foam height will be greater and more easily fall over the edge and into the cup and B) When the bubble does pop on the domed lid it will travel along the slope into the cup rather than into the neck. During my research on this I found that every single person who ran their skimmer without the lid saw an increase in skimmate production.

The next mod I executed was the standard neck cleaner with a squeegee. There's really nothing special here as other have done it and many companies sell neck cleaners for about triple what it would cost you to do it yourself. Of course the benefit to a neck cleaner is that there is a certain point when the neck is so dirty that skimmate production slows down and it must be cleaned. With the neck cleaner you will always have peak performance from a clean neck perspective.

Finally, the last mod I added was a complete wash down system. I thought about what I'd have to do to keep my skimmer running great and how could I automate it and the bottom line is you have to clean the neck and wash the cup. So with this mod my skimmer cup and domed lid will get a blast wash down from the micro jet sprinklers I installed. This will be fed by a pump in a separate RODI container. I'll also add a solenoid to the drain to open in conjunction with the cleaning process.

Of course all of this will be automated daily with my Apex including the use of the float switch inside the skimmer cup.

There are still a few more adjustments I need to finish. I'll order the squeegee from Avast and I need to figure out a better way to secure the float switch. For some reason I'm having trouble locating hollow plastic threaded pipe. I may change the orientation of the manifold too. I'm not sure how I want to secure it as I'm still working on acquiring equipment for my latest build. It will most definitely have a union for easy removal. I just installed it for the photographs.

 

[Theokie]

very interesting following along.

 

[TheThingIs]

Looks good. I'd tend to say that the float switch won't be very reliable and will probably gunge up and stick alot. I'd suggest using a pressure switch which works flawlessly. I use the avast ato kit connected to my apex to drain the cup. HTH

 

[gbru316]

Looks good. I'd tend to say that the float switch won't be very reliable and will probably gunge up and stick alot. I'd suggest using a pressure switch which works flawlessly. I use the avast ato kit connected to my apex to drain the cup. HTH

If the switch is to empty the cup, I'd recommend against any "mechanical" switches and opt for an optical sensor. Anything mechanical (including pressure switches) is capable of being fouled in the collection cup.

 

[slief]

Interesting design.. The reason for the flat lid is so that the bubbles are pushed outward towards the collection cup but the pressure of the bubbles below. When the bubbles hit the lid which is in close proximity to the skimmer neck, the bubbles are forced outward and into the cup. The bubbles have enough density at the top of the column that any DOC's trapped in the bubbles if they pop would remain in the top of the foam column and ultimately be pushed outward.

Your dome approach will create less pressure on the top of the foam column. It would allow the foam to dry out more as it pushes its way to the top of the dome. This would make it more difficult for the bubbles to overflow into the cup and also make it more difficult to tune the skimmer. You will notice that all skimmers have the lid setup in relative close proximity to the skimmer neck. You could accomplish the same thing as your dome by raising the lid further away from the neck however, there is a reason why the lids are in close proximity to the neck which is what I described above.


Interesting idea for your wash down. What are you going to feed it with? I made a custom wash down for my Alpha 300 and found that using an RODI pressure pump didn't put out adequate water volume. I ended up using a solenoid and connected directly to a hose spigot I had plumbed into a closet next to my tank. The tap water pressure and volume works great. In the end, I rarely use the wash down but it comes in handy when I want to rinse the collection cup every so often. That said, since the washdown is limited to the collection cup area, there is no real point in wasting RODI water on it. Your nozzles are well below the top of the skimmer neck. As such, the water will be contained within the cup provided you don't overfill it, in which case, a little bit of water will be the least of your concern. On the other hand, RODI water shouldn't clog up the sprayer nozzles like tap water would from additional calcium or other stuff contained in tap water.

Here is the approach I took which was modeled after the Aqua Driver Skim Clean/Bubble King wash down and worked well with my Skim Clean SCH/Wiper. Putting the tiny holes in the tubing was a nightmare and took a couple attempts to get it just right. I used needle that I held over the stove to put the holes in the tubing.

When I sold my Alpha 300 and upgraded to a Supermarin 250, I ordered a new lid from Aqua Driver that had the wash down already installed. I reused my original wiper and motor on the new lid which saved money. In the end, I didn't feel like making my own wash down again and got the new lid for a reasonable price. It works great too although I rarely ever need to use it.

 

[slief]

If the switch is to empty the cup, I'd recommend against any "mechanical" switches and opt for an optical sensor. Anything mechanical (including pressure switches) is capable of being fouled in the collection cup.

Optical won't work well at all. Once it gets coated with skimmate, the optics will cease to work. The sensor would have to be installed outside the cup which could be problematic due to the humidity and buildup inside the cup. The mechanical float switch would be far more reliable as long as it's kept clean. A pressure switch would be better though.

 

[gbru316]

Optical won't work well at all. Once it gets coated with skimmate, the optics will cease to work. The sensor would have to be installed outside the cup which could be problematic due to the humidity and buildup inside the cup. The mechanical float switch would be far more reliable as long as it's kept clean. A pressure switch would be better though.

Depends on the wavelength of light being used outside of the cup, the gain of the detector and the threshold. Moisture buildup could be accounted for.

 

[4Hummer]

Depends on the wavelength of light being used outside of the cup, the gain of the detector and the threshold. Moisture buildup could be accounted for.

Or use a pressure sensor.

 

[CuzzA]

All good points. The float switch is certainly a concern. Fortunately, as we know, the Apex can be a great tool for any system to communicate with us and I plan on programming an alert every time the system goes through a wash cycle. This way if the switch did get stuck I would know it. I'll look into other solutions that have been mentioned. The plan is to let the cup fill up with water and also hopefully the sprinklers can keep the switch relatively clean.

I don't pretend that I'll never have to clean the cup ever again and this system has not been tested yet. There will still be the normal pump/venturi maintenance and occasional cup cleaning. Fortunately the wash down system was just a few dollars and the skimmer lid is $10 if I find that the system as a whole doesn't work.

I understand the point about the lid forcing the bubbles into the cup. But again, how many of those bubbles are popping and reducing the efficiency of removal. Logic tells me that without any restrictions the foam head will continue to build and fall over into the cup or reach the dome and run off the slope. I didn't come up with this out of the blue. I read a thread where people were finding a substantial increase in skimmate without the lid, albeit a stinky messy increase, and I did more research only to find many more reporting the same thing. This leads me to believe that less restrictions on the foam head will produce a more efficient production of skimmate. In fact a member in my local club stated he used a bowl once when he purchased a used skimmer that was missing the lid and he was surprised at how well it worked.

One of the problems with the lid debate is we don't have any test results. I couldn't find any info anywhere. Could that be because I am in fact wrong OR as I would like to believe it's a cost issue. Say there would be a 20% increase in skimmate production, but a manufacture would have to charge $50 more for a domed lid. Well, as competitive as this industry is I doubt any "business" is going to corner themselves into less profits as so many people overlook quality for price.

The wash down system likely wont blast away every bit of grime, but hopefully it will keep the cup relatively clear from a visual aspect so that I can still see that everything is functioning as it should. It does have a sprinkler within the dome as well so that should help.

Slief, I don't see in your pictures the sprinkler heads that you used. Just to clarify, the ones I purchased are different than the standard drip line heads. They are much smaller and are designed for 1/4 inch tubing. As with any pipe or tube, it can only handle so much volume. Hopefully one of the many spare pumps that I have will be able to provide enough pressure. The plan is to just keep a pump hooked to the manifold in a container of ro/di water and blast everything once per day until the cup is full and activates the float switch which then opens the solenoid. I don't believe I would be wasting much ro water. I even thought about using ro waste water, but I don't know how much would end up getting in the system and I likely wouldn't take that risk.

I'll water test it in the next couple days and post a video of my results. A skimmate production test won't happen until I receive the new tank and I'll go ahead and buy another lid so that I can make an accurate comparison.

 

[slief]

All good points. The float switch is certainly a concern. Fortunately, as we know, the Apex can be a great tool for any system to communicate with us and I plan on programming an alert every time the system goes through a wash cycle. This way if the switch did get stuck I would know it. I'll look into other solutions that have been mentioned. The plan is to let the cup fill up with water and also hopefully the sprinklers can keep the switch relatively clean.

I don't pretend that I'll never have to clean the cup ever again and this system has not been tested yet. There will still be the normal pump/venturi maintenance and occasional cup cleaning. Fortunately the wash down system was just a few dollars and the skimmer lid is $10 if I find that the system as a whole doesn't work.

I understand the point about the lid forcing the bubbles into the cup. But again, how many of those bubbles are popping and reducing the efficiency of removal. Logic tells me that without any restrictions the foam head will continue to build and fall over into the cup or reach the dome and run off the slope. I didn't come up with this out of the blue. I read a thread where people were finding a substantial increase in skimmate without the lid, albeit a stinky messy increase, and I did more research only to find many more reporting the same thing. This leads me to believe that less restrictions on the foam head will produce a more efficient production of skimmate. In fact a member in my local club stated he used a bowl once when he purchased a used skimmer that was missing the lid and he was surprised at how well it worked.

One of the problems with the lid debate is we don't have any test results. I couldn't find any info anywhere. Could that be because I am in fact wrong OR as I would like to believe it's a cost issue. Say there would be a 20% increase in skimmate production, but a manufacture would have to charge $50 more for a domed lid. Well, as competitive as this industry is I doubt any "business" is going to corner themselves into less profits as so many people overlook quality for price.

The wash down system likely wont blast away every bit of grime, but hopefully it will keep the cup relatively clear from a visual aspect so that I can still see that everything is functioning as it should. It does have a sprinkler within the dome as well so that should help.

Slief, I don't see in your pictures the sprinkler heads that you used. Just to clarify, the ones I purchased are different than the standard drip line heads. They are much smaller and are designed for 1/4 inch tubing. As with any pipe or tube, it can only handle so much volume. Hopefully one of the many spare pumps that I have will be able to provide enough pressure. The plan is to just keep a pump hooked to the manifold in a container of ro/di water and blast everything once per day until the cup is full and activates the float switch which then opens the solenoid. I don't believe I would be wasting much ro water. I even thought about using ro waste water, but I don't know how much would end up getting in the system and I likely wouldn't take that risk.

I'll water test it in the next couple days and post a video of my results. A skimmate production test won't happen until I receive the new tank and I'll go ahead and buy another lid so that I can make an accurate comparison.

Regarding the skimmer lid, there are some very very expensive (no expense spared) skimmers out there and there is one thing they all have in common with each other. The skimmer lid. Big or small, short or tall, cheap or ungodly expensive. When the bubbles pop, the DOC's remain at the top of the foam head and end up in the cup because the bubbles and foam column force them that way. They don't go back down into the skimmer/water. If a skimmer is allowing the waste to go back down the neck into the skimmer body/water, then there is either a serious issue with the skimmer design or the setup. A properly designed and tuned skimmer will not allow the DOC's to travel back down into the water regardless of how many bubbles pop. With the skimmer tuned and operating properly, that is impossible as the DOC's attach to the bubbles. At the same time the neck of the skimmer is inundated with rising bubbles to prevent just that scenario and instead force the DOC's out the top. While the dome is a neat idea, you are overthinking things and complicating something that doesn't need improvement as the cup design of modern skimmers is a science that was proven long ago and works amazingly well. That said, I can't fault you for your ingenuity and willingness to experiment. It looks pretty damn cool regardless of how it functions in the end.

As for my wash down, I didn't use sprinkler heads. That 1/4" tubing has little pin holes every 1/2" or so. Probably not as effective as your little sprinkler heads but it works well enough to clean the collection cup.

 

[CuzzA]

Regarding the skimmer lid, there are some very very expensive (no expense spared) skimmers out there and there is one thing they all have in common with each other. The skimmer lid. Big or small, short or tall, cheap or ungodly expensive. When the bubbles pop, the DOC's remain at the top of the foam head and end up in the cup because the bubbles and foam column force them that way. They don't go back down into the skimmer/water. If a skimmer is allowing the waste to go back down the neck into the skimmer body/water, then there is either a serious issue with the skimmer design or the setup. A properly designed and tuned skimmer will not allow the DOC's to travel back down into the water regardless of how many bubbles pop. With the skimmer tuned and operating properly, that is impossible as the DOC's attach to the bubbles. At the same time the neck of the skimmer is inundated with rising bubbles to prevent just that scenario and instead force the DOC's out the top. While the dome is a neat idea, you are overthinking things and complicating something that doesn't need improvement as the cup design of modern skimmers is a science that was proven long ago and works amazingly well. That said, I can't fault you for your ingenuity and willingness to experiment. It looks pretty damn cool regardless of how it functions in the end.

As for my wash down, I didn't use sprinkler heads. That 1/4" tubing has little pin holes every 1/2" or so. Probably not as effective as your little sprinkler heads but it works well enough to clean the collection cup.

But have they tested it? If so, where's the proof!!! Either way, the decision was easy being that a replacement lid is $10. If I find no improvement or a reduction in skimmate, then it's no big deal to swap out lids. This project was so cheap, simple and took very little of my time plus I enjoy tinkering with this stuff and if I happen to stumble upon something that can add value to the reefing communinity than that's even better.

Slief, I will document this experiment and if my hypothisesis is true you'll be the first to hear about it.

 

[CuzzA]

Apparently I'm not the only one who has thought of this. After a little more surfing the net I came across this. RK2? I know nothing about them. I read they supply the commercial market more so than the consumer market. Nevertheless, that is a domed skimmer lid.

 

[slief]

Apparently I'm not the only one who has thought of this. After a little more surfing the net I came across this. RK2? I know nothing about them. I read they supply the commercial market more so than the consumer market. Nevertheless, that is a domed skimmer lid.

Interesting... RK2 is well known for their commercial systems.. One thing that differentiates that skimmer from yours as well as most others is the conical neck inside the cup. That makes a difference as to how the foam is forced up the neck and the pressure behind the foam. That said, That looks like a really cheaply built skimmer. I've never seen nor heard of that particular skimmer in use by anybody, let alone forum members and I've been in this hobby a long long time and had dozens upon dozens of skimmers over the last 27+ years... If it was such a great thing, I'm sure we would see them and I know several stores that have run the RK2 commercial systems. I'd venture to guess that skimmer was not a very popular one.

As for whether the other skimmer manufacturers tested the domed lid, I'd suspect the high end ones have tested it in the interest of performance. Especially if a competitor was employing that type of a lid. I'd surmise that a lot of R&D went into some of the more popular skimmer designs. At least by the original designers. Given that so many skimmer body designs have been copied by other companies, a simple thing like a dome lid would be worthy of testing and implementing if it were worth the effort and companies like Royal Exclusive or Deltec let alone others would be taking advantage of such a simple performance enhancement. Hypothetically speaking.

As part of your experimenting, I hope you run the skimmer with both the standard lid and your domed mod so you can formulate an objective opinion. Either way, like I said, I commend your ingenuity and willingness to try different things and experiment like that. It certainly looks cool. I don't think you will see any apprecialble difference from the dome but as long as you had fun and provided it doesn't hamper the skimmers performane too much if any, why not dare to be different! :beer:

By the way, from one fisherman to another, nice Mahi or DoDo as we refer to them out here!

 

[Gorgok]

I could imagine a domed lid would actually be useful if the highest point were basically the same height as a flat one (or at least not so high it takes more effort to hit the lid with foam). This means the rest dips down past the neck, but so be it. With a flat lid you have to force the foam to travel horizontally with more foam, which works well enough usually. But with a domed lid runny foam could cling to the lid and have gravity pull it towards the sides in addition to being forced with more foam. The same runny foam could fall off a flat lid back into the neck, only to get beaten into foam again and rise. A really dry foam may not benefit, as it may not run down anything.

Would be an interesting test, one of many things in skimmer design, to have done side by side...

 

[slief]

One more bit of advice. Double check where the wires go into that float switch. Some switches aren't properly sealed for salt water use. If the opening at the top where the wires go into it isn't sealed with glue or sealant, do yourself a favor and add some sealant to the hole. Otherwise that switch will fail prematurely and create a closed circuit from corrosion where the wires meet the contacts inside the switch.

 

[CuzzA]

I could imagine a domed lid would actually be useful if the highest point were basically the same height as a flat one (or at least not so high it takes more effort to hit the lid with foam). This means the rest dips down past the neck, but so be it. With a flat lid you have to force the foam to travel horizontally with more foam, which works well enough usually. But with a domed lid runny foam could cling to the lid and have gravity pull it towards the sides in addition to being forced with more foam. The same runny foam could fall off a flat lid back into the neck, only to get beaten into foam again and rise. A really dry foam may not benefit, as it may not run down anything.

Would be an interesting test, one of many things in skimmer design, to have done side by side...

I agree. I thought about making my own dome, but a $3 acrylic bowl made that decision easy.

One more bit of advice. Double check where the wires go into that float switch. Some switches aren't properly sealed for salt water use. If the opening at the top where the wires go into it isn't sealed with glue or sealant, do yourself a favor and add some sealant to the hole. Otherwise that switch will fail prematurely and create a closed circuit from corrosion where the wires meet the contacts inside the switch.

Yes, it's sealed. I have one in everybody of water on my current system, including the skimmer. Good point though.

 

[CuzzA]

I'll do a 24 hour back to back test with both lids. I'll make sure the cup is clean for both tests and feed the exact same type and amount of food for each test and measure how much skimmate is collected. If the results are inconclusive, I'll add another 24 hours to each test and hopefully I'll have an answer.