No directions for sponge filter

[White Worm]

Please let me know which way is better.

sponge filter.bmp

[White Worm]

Sorry I couldnt get the picture bigger. I need to know if you attach the airstone directly to the lower attachment or if you run tube down to the bottom and then attach airstone?

[Ryan]

I don't run my airlines through the whole sponge. I attach them right to the top piece. I just hook the airline directly to it. You can use an airstone if you want. Here's a pic of a Hydro sponge. I drew a red circle where I attach the airline.

Ryan

[cobaltblue]

Im same as ryan, i dont use an extra airstone, but the air line that feeds into the top. This provides enough surface agitation for my tanks.

[RyanH]

I don't think there is any one right way to run your sponges.

I like to use airstones and a fairly low airflow rate. This is because I don't like to rely on my sponges for mechanical filtration. Rather my goal is to nurture a large colony of nitrifying bacteria without having to worry as much about sponges getting clogged up with waste. This means less maintenence and because I'm not having to clean them out as often. It also means a larger and more established colony of bacteria because it isn't getting rinsed and squeeze away due to constant cleanings.

I also think using airstones give a more even flow of water through the sponge because you have a large number of small bubbles running up your tube rather than have a few large ones.

Again, this is personal preference. Yeah, I'm anal.

-Ryan

[White Worm]

Why do you think they have the lower attachment point inside? I thought you would get better filtration through the sponge if you had the tube running through to the bottom??? I just dont have alot of experience with a cycled sponge yet. The air stone just keeps the bubbles smaller. I thought it would increase aeration, am I wrong?? Thanks for answering my questions

[RyanH]

I for one, agree with you.

I don't bother with the attachment points either. I just run the tube down and attach an airstone.

[alpine]

Well, this is my experience . Experience of only 8 months of keeping three 75 gallon tanks with discus. I added a small line inside the Hydros...it made sense to me that was the way to go to draw more water through the sponge...I still think I was right ...but....the end of the small air line kept getting clogged and air did not want to flow that well through it....
I took all the small air lines off the inside of my Hydros and everything is working a lot better now...

roberto.

[Cosmo]

I run a small length of airhose from the top connector to a small airstone that sits about 1/2 way inside the base. Like RyanH, I prefer to keep my mechanical and biological filtration separate so I don't pump a strong stream of air through the filter. The airstone does a couple things, 1 - small bubbles make for a more even flow of water, and 2 - it makes the filter much quieter - and keeping the source lower IMO insures a more even flow of water through the entire sponge

Jim

[White Worm]

I tried it different ways in two tanks now. I tried it with nothing inside and then with tube and airstone halfway down inside. I find that it does pull more through the sponge with the tube halfway down inside. For my breeding pair, thats all that is in the tank so I need it to do all the filtering plus I do about a million water changes which keeps the water clean too. I think I may try one with the tube all the way at the bottom of the inside with the airstone and see if the flow through the sponge increases more. Thanks for the input, sometimes just got to experiment and find what works best for your situation. Mike

[JimmyL]

I don't know the attachments 0f your picture. The principle behind a sponge filter is how much negative pressure can be generated by the air bubbles. A certain distance that the air bubble have to travel and the size of a single bubble plays an important factors. Negative pressure at the center of the sponge needed to suck the surrounding water into the sponge and expell through the top of the pipe that filters the water in your aquarium. Each factor is directly proportional to the amount of water getting through the sponge filter. Efficiency is measured in this way. Taking off the rising tube that decreases the distance an air bubble have to travel also decreases the amount of negative pressure generated by the "Venturi" which stated that the air travel through a restriction (narrow path) creates a neagative pressure that draws the water into the filter. In fact I together with my medical director created a first "Winliz" nebulizer used in the US army for inhalation treatments during the Vietnam War. When the army had trouble keeping their engine running under hot weather. The first fuel injection car was created with the help of "Winliz" jet nubulizer and applied into the carburator in an army jeep. The pattern somehow end up in every car in N. America that made the doctor very rich and his student got nothing. Just a pat at the back " Good work, you pass".
Jimmy

[hexed]

Mike,
I cut a small piece of airhose and attached it to the underside of the connecting plate and added the airstone to that. Then attached the airhose to the top of the plate. The airstone goes to the bottom of my sponges and I think it seems to work much better. The entire sponge now filters the water instead of just the top part. If you need pics just let me know.

[White Worm]

Hexed..... Thanks for the tip, I actually sat and watched the filters in all different configurations, I agree that there is a better and more uniform flow with the tube inside and an airstone attached at the bottom of the filter, thanks, Mike


Jimmy..... I thank you for the advice I think Just a little advice, in the future, try to speak a little less scientific about a simple subject. I understand the venturi principle completely because I was an aircraft mechanic for the air force for the last 13 years with specialties being hydraulics and fuels. Some people on here though would not have had any idea of what you speak. I was just asking some here which way they preferred. No insult intended, friends still??

[nacra99]

Please let me know which way is better

Oh Cool!... I thought that i was the only person on the face of this earth that was wondering the that.

Actually, conducted some experiments on using bubbles to uplift water in my lab a few years back as part of our hydrodynamics research.

FYI, (trying not to be too scientific) what we did find was that with the airstone lower down in the filter, there was a greater overall negative pressure on the intake...i.e it sucks in water more powerfully (not necesarily quickly). The same effect was observed by extending the uplift tube upwards at the top instead of moving the airstone down.

So suction is due to the cumulative effects of the enclosed bubble column. I.e. the lifting forces of the bubbles add up. But it doesn't vary linearly (which is what we were investigating).

So the amount of suction is not simply due to the postion of the airstone, but more importantly how tall the enclosed bubble column (uplift tube) is.

IMHO, for aquarium purposes, there is no significant difference whether the air-stone is below or at the top of the filter. I keep mine at the bottom (at no particular reason).

Cheers
Marc