Sihponing rate and return rate

[porc]

pict of the "skimmer" cylinder...

[porc]

last pict. underwater view.

oh yes. the green tubing is there to draw out the air to create the siphon in the 1st bend.

the cylinder is 50mm and the overflow piping is 25mm. my return piping is 13mm.

[desm0nds]

hi delirium, thanks for sharing. But dun really can figure out from the diagram how is the setup like. You mentioned that you have 2 return path into the tank. One just benethe the water surface and the other half way down. Assuming that I get the orientation right, the green path, i.e return path is splitted across the Tee. One to left and one to right. ey....so how should I look at it to see theoutlet beneath the water level and half way down tank?

Appreciate if you could elaborate further on this.

Porc, the pictures are fine. thanks. Taken with a phone camera?

When the korean design the Hyundai, nobody knows that the jap are working on the Toyota. In short, originality varies among people pt of view.

Since we are talkin about this extra cylinder idea, one of my friend did came up with somewhat similar. Only this time, the sylinder is outside the tank. Problem is, the cylinder is able to hold up to 3L of water i.e. 3Kg of weight and I couldnt possibily hang it on my tank's wall. So the idea was abandoned. But its a great idea to have it inside the tank.

you are using 1200l/hr pumping rate. how do you deal with water circulation in the main tank? I had experiment with a 1600 in my tank and by positioning it abt 4 inch below the water top, I get a small current in the tank. Enough to stir up small debris. Initally it did stir up the sand. But after I reposition its outlet to blow at the rocks, the current breaks apart but still able to stir up small debris.

My whole idea is to be able to have a steady water current in the tank to disturb the bottom debris so as to be able to suck in by the siphoning in the middle inlet to be collected in the sump filter. And I need a good water cycle to the filter system so as to have cleaner water in the main tank. That's way the idea for a sump tank. Reduce nitrate level, reduce growth of diatoms etc. Eventually lesser maintenance work in term of water changing and sandbed disturbing to remove diatoms.

Well didnt know that it involved so much studies and experiment. But since I started the idea, I will definitely follow thru till the end. For the sake of a cleaner environment for my fishes.

[porc]

okie... understand your reasons for wanting a bottom inlet... let me try to analyse...

I think you can drill some holes towards the lower half of the cylinder, but the holes cannot be too big. must keep it small so that there will always be extra to overflow from the top. Also, when the pump fails the water level in the main tank will fall all the way down L2. If your sump can hold that amt of water then i don't forsee a problem...

[porc]

hi delirium, thanks for sharing. But dun really can figure out from the diagram how is the setup like. You mentioned that you have 2 return path into the tank. One just benethe the water surface and the other half way down. Assuming that I get the orientation right, the green path, i.e return path is splitted across the Tee. One to left and one to right. ey....so how should I look at it to see theoutlet beneath the water level and half way down tank?

Appreciate if you could elaborate further on this.

I think he mentioned that he already has holes drilled into the tank. In that case he has a direct overflow and not a siphon overflow. We precisely do not want to drill our tank for fear of breaking it, so his solution is not suitable for us...

[desm0nds]

ok, I have modified the design a bit more, hoping that it will resolve all the outstanding issue.

Firstly, the siphoning path:

1) As can be seen from the picture, A double U channel is used to restart siphoning after recovery from pump failure.

2) A surface skimmer and a mid tank inlet.

3) A ball valve at the bottom to regulate the flowrate into the sump.

4) A "non-full" siphoning path and also act as a bleed path for access water to flow back into the main tank when ball valve needs to be used.

There is still 1 point here need to be clarify. Lx. This level. Should it be below the mid tank inlet or it doesnt matter at all?

[desm0nds]

Next is the returned path:

1) A ball valve is again used to regulate flowrate into main tank.

Excess water will flow back into sump.

2) A reverse siphoning breaking hole at the outlet below the water level.

Well, can this system works?

[porc]

great idea on the bleed path! Lx does not matter, but do try to eliminate/minimise bubbles creeping into the siphon bend by having as long a tube as possible for the piping just below the skimmer's "expanded" intake.

I also suggest the following building procedure. don't fix the skimmer input and tubing to the t-joint first. Run your full system and see where L1 stabilises to. then measure the length of the pipe required such that the skimmer is just below the water surface...

Your design seems real good now. Let us know when it's done and working. All the best!!!

[desm0nds]

Cool! Finally I can start to work on it. Will let you guys know the result once its done. Got to go shopping for the "material".

[desm0nds]

Hi guys. I am back. I have followed exactly the modified design earlier and the result.....

The flow rate is indeed just to slow. Apparantly when the 2nd U is lowered, the flow rate increased. As mentioned in another thread by someone else, the column between L1 nad L2 is just too little and thus the pressure required to push the water up the last U and down to the valve.

But if I lowered the U channel in order to achieve a higher flowrate, my minimun water level will be very low and I would need a huge capacity sump tank to contain the over flow should the pump failed.

But it is not hopeless yet. I have came up with another design. Double siphoning breaking system. This method will allow a fast flow with the U channel lowered and yet have a higher minimum water level.

Refer to the diagram.

During normal operation when water level level is way above siphon break point 1. There is a full siphon in the main tank to the pipe. Water flow rate will be fast due to the outside the tank being low. The pressure in the water level difference will be enuogh to create a fast flow. And the theory of what goes in must come out still works.

When water level falls to Siphon break point 1, the siphoning from the main tank water into the pipe will break. Whe this happened, water level in pipe will be undergoing a mini-siphon break when the water level in the pipe decrease further. The water level will be trapped at siphon break point 2.

When water level in main tank raises way above siphonin break point 1, siphoning from main tank into pipe continues on.

Hooray!

[desm0nds]

Detailed picture

[porc]

Hi guys. I am back. I have followed exactly the modified design earlier and the result.....

The flow rate is indeed just to slow. Apparantly when the 2nd U is lowered, the flow rate increased. As mentioned in another thread by someone else, the column between L1 nad L2 is just too little and thus the pressure required to push the water up the last U and down to the valve.

Hi Desmonds,

Sorry to hear of your unsuccessful attempt . Puzzles me why you would experience low flow rate. Has the tank level stabalized yet? Or is it that you found that your overflow is not coping with return flowrate and you had to abort the test before your main tank overflows? If this is the case then yes we may have allowed for insufficient L1-L2.

  But it is not hopeless yet.

All the way man... that's the spirit...

When water level falls to Siphon break point 1, the siphoning from the main tank water into the pipe will break. Whe this happened, water level in pipe will be undergoing a mini-siphon break when the water level in the pipe decrease further. The water level will be trapped at siphon break point 2.

I do not have time now to fully analyze your diagram and figure out what you are trying to achieve. But from a quick glance it seems that the water level will not fall below siphon break point 1. Maybe tonight I'll get back to this.

Cheers...

[porc]

consider this mod to your new design... haven't thought in detail... you can help think thru whether this will work.. lower the second bend and add the pipes in red. water level in tank will drop to same siphon break point as indicated, but water level in the red pipe will drop to L2.

arrggh.... this is distracting me from my work... okay last post for now... will be back tonight...

further edit: damn!. just realised this design is no different from yours, only structually different in terms of piping. think I get your idea now... I still think water level will not drop below siphon break point 1, but with this you can increase the L1-L2 difference without emptying the main tank. brilliant!!!

[desm0nds]

Porc, maybe I should not say dropped below siphon break pt 1. Rather, I should say dropped till siphon break pt 1. ie. minimum water level in tank. You agree on this?

Btw, apologies for distracting you from you work. :-P

As for the previous design, you are right about that when u guess that I had aborted the test before my main tank get overflow. But really lor, the flowrate is really really very slow. The water is just about 3 cm away from the very edge of the main tank before.....

[Eric]

consider this mod to your new design... haven't thought in detail... you can help think thru whether this will work.. lower the second bend and add the pipes in red. water level in tank will drop to same siphon break point as indicated, but water level in the red pipe will drop to L2.

arrggh.... this is distracting me from my work... okay last post for now... will be back tonight...

further edit: damn!. just realised this design is no different from yours, only structually different in terms of piping. think I get your idea now... I still think water level will not drop below siphon break point 1, but with this you can increase the L1-L2 difference without emptying the main tank. brilliant!!!

Save all the trouble, get a I~box by I~AQUA, neat,safe,.....tested and proven by many.

[desm0nds]

Thanks Eric.

No doubt I-box is the solution, what it lacks here is the fun and the satisfaction. Its the DIY thing lor if you get what I mean.

Different people could have different view and there's no doubt about that.

Anyway, how much does that I~box cost? :-P

[porc]

Porc, maybe I should not say dropped below siphon break pt 1. Rather, I should say dropped till siphon break pt 1. ie. minimum water level in tank. You agree on this?

yes, i agree that under normal failure water will drop only till break point 1. Looks like we are in agreement on this and you are good to go...

Btw, apologies for distracting you from you work. :-P

It's not you lah... It's the damn ease of access of the internet and this site. I specifically withheld myself from coming in last night (so that I can sleep early cause I need to work hard today) and this morning but by lunchtime, beh tahan already... See! now I'm back in again, but at least I finished my work for today... guess we're bitten by the reefing and diy bug to think of solutions to all these challenging problems...

As for the previous design, you are right about that when u guess that I had aborted the test before my main tank get overflow. But really lor, the flowrate is really really very slow. The water is just about 3 cm away from the very edge of the main tank before.....

just as I thought. so technically speaking it's not that the flow rate that is slow. it's just that insufficient height has been built up to increase the flowrate. For my one at home the L1-L2 height difference is only about 3 cm, but I guess this will change depending on your pipe size and flow rate.

No doubt I-box is the solution, what it lacks here is the fun and the satisfaction. Its the DIY thing lor if you get what I mean.

true! you have the spirit and determination man... i simply gave up on the bottom intake spec when I made mine...

Anyway, how much does that I~box cost? :-P

Last time I saw it costs enough to build me 10 overflows...

cheerios

[rockfish]

hi desmond!

if u still serious about DIYing the overflow system, email me.. i can give u thje details. i have made this system before and face the same problem.

so if u dun mind a few pieces of wat i call .. true life experiences!!

mail me .. i'll help as much as i can ..

long live DIYERs!!

[desm0nds]

Thanks Rockfish. The design is cool but I am already in the mist of building mine. As mentioned before, I will make use of your design on my other fren's tank which are more clutter which don't require a bottom intake. Mine is very empty so a bottom intake and a surface skimmer is necessary.

Ok now for the judgement day. I have completed the overflow and put on real live test on my 3ft tank. Result so far so good. Waterflow rate is matching with my 2500l/hr return pump. Both surface skimmer and bottom intake are doing their job well.

I have attached some pictures. Any comment from you expert out there?

Here is the first picture. The intakes.

[desm0nds]

followed by the double U channel outside.

For this part, I copied the design posted in the this forum and also from rockfish.

[desm0nds]

The output will eventually lead to a ball valve before it gets into the Marinda Strawberry plastic bottle "filter" compartment.

[desm0nds]

The water will go by the sand bed and to the return pump. There is a ball valve in the return pump path to work as a bleed path in case the pump rate is faster than the siphoning rate. Currently, it is closed for max. return pump power to main tank. The siphoning rate instead has to be opened 3/4 wide to keep the system balance.

[desm0nds]

So that is the system. So far, its the 3rd day of test.

No sign of sump overflow or tank overflow still.

I read somewhere that with the sump, the water temperature should falls 1 degree celsius lower than before. But its not true for my case leh. Still the same as before at 31. Rather on the high end right? sigh...

I should starting looking at the DIY chiller thread...

[porc]

So that is the system. So far, its the 3rd day of test.

No sign of sump overflow or tank overflow still.

Cool bro... congrats...

I read somewhere that with the sump, the water temperature should falls 1 degree celsius lower than before. But its not true for my case leh. Still the same as before at 31. Rather on the high end right? sigh...

but you have an extra pump on there generating heat now... maybe that's the reason...

I should starting looking at the DIY chiller thread...

hehe... this one totally way out of my field...