Pond Boss Forums AERATION Systems questions Keeping Ice Off My Dock

Hello, I'm new to the forum and am looking for some advice. I live in Maine on a lake and have a permanent dock that I've been deicing for 6 years. I have a Vivosun 102W 1750 GPH commercial air pump. Until this year I used the manifold (10 connections) that came with the pump. While it worked OK all of the connections are barbed and tended to vibrate off resulting in me going into the lake to fix it. I've built a new manifold and am not getting air flow to all the stone diffusers (9) that I was with the old manifold. Below are some details. Any advice is greatly appreciated.

1) Vivosum 102W 1750GPH commercial air pump
2) 9 - 8"x1.52 cylinder stone diffusers.
3) The manifold is built using 1/8" brass fitting and 1/4" Sharkbite connectors for the 1/4OD tubing. The manifold has 5 connections left and right of center where it connects to the pump. Each connection does have a shut off valve.
4) The pump is in a custom box under the crib that the dock is built on.
5) The longest run from pump to diffuser is 16' and the shortest is 3'.
6) The water depth varies but during winter month is 1 - 2' closest to shore and 4-5' furthest from shore.

I am getting good flow through one diffuser, the one connected to the last position (I'll call it 5 Left for discussion purposes) on the manifold on the left side which is the 2nd closest diffuser to the pump. I am getting minimal air flow from position 4 Left but not enough to keep ice out and no flow for the other 7 diffusers. I wasn't having this problem with the "barbed aquarium diffuser". Apologies for the long post but thought details would help.

Welcome to the forum!

I use 1/4" welding hose to feed my diffusers in the hauling tanks and I use barbed connectors. I found that if I don't use a hose clamp on the barbed fitting the hose would come off. Were you using a hose clamp on the barbed fitting?

Why did you use a 1/8" fitting instead of the 1/4" fittings?

I would take the hoses off of the manifold and check the manifold to ensure that none of the 1/8" fittings are plugged. I have seen a piece of Teflon tape plug a small fitting before. I am (maybe incorrectly) assuming that some sort of thread sealant was used on the threaded connectors? Or is there no threaded connectors?

Are the airstones the same ones that you have used previously? Have you tried swapping airstones to see if it's the airstone at that port or something else? If yoiu are using airstones and not a membrand diffuser, do you clean the airstones yearly in muratic acid?

Do you have all the fittings 100% open or are you trying to adjust them to get the same amount of flow through each one?

For every 12" of water depth there is 0.433 psi backpressure. If you don't have the hoses all exactly the same length, the airstones at exactly the same water depth, and the same air resistance in the different airstones, you cannot run them all 100% open. You have to throttle down the ones in shallower water/shorter hose.

Thanks esshup for the response and welcome....very helpful. Below are answers to your very good questions. I would like to post pics of the old and new manifold, as well as the dock I am deicing, but can't figure out how to post pic's ... just links to pics. If there is a way to do that, please let me know?

1) The old manifold is small, very small, I couldn't file clamps small enough to work. Even if I could the connections are so close together I don't think it would work.
2) I used 1/8" fitting because that's what is required coming out of the pump. I suppose I could have gone 1/8" to 1/4" right out of the pump instead of transitioning out of the manifold itself which is built with 1/8" Tee's connected by 1/8"x1/8" hex nipples. Do you think transitioning from 1/8" to 1/4" out of the pump vs. how I did it would help?
3) Yes indeed I am using plumbing tape on all threads that make up the manifold. I will check and make sure none are plugged.
4) Yes the air stones are the same as I've used for 3 years now .... without cleaning ever. I will clean them in muriatic acid.

I will make all 9 of the tube runs the same length. If I do that the total length will be 144' of tubing. Do you think the pump is "big" enough to handle that? I can make all the stones the same depth if they are 1' below (given current lake level - we are in a drought in Maine) the surface of the water. Do you think that depth is deep enough for deicing?

Thanks again, I appreciate it.

To post pics here I find it easiest to first post them to Imgur then put the link in the thread. You must use an on-line hosting site first (imgur or similar). https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92443#Post92443

I would have gone 1/8" to 1/4" right out of the pump. Making the lines the same length won't matter. You will still need to balance out the lines using the valves going to each airstone and restricting the air flow to the shallower ones. The difference in the water depth will require balancing the lines

When we install a remote valve box for an aeration system in a pond, the threaded fitting coming out of the compressors are either 1/4" or 3/8". It's immediately jumped up to 1/2" and if we are using a remote valve box (remote manifold) that is a distance from the compressor, we jump up to 1" black poly tubing and neck it back down to 1/2" or 5/8" at the remote manifold, and run that size weighted tubing in the pond to the diffusers.

The bigger the line ID the less restriction on the system and the more cfm the compressor will move, plus there is less strain on the compressor over time.

Thank You. I'm inclined to re-build the manifold. I'll come out of the pump at 1/8" and transition to 3/8" for the rest of the system. Do you have a recommendation for a diffuser for a 3/8" tubing?

Thanks
Tim

Foe de-icing, you want coarse bubbles. Your compressor output is 3.88 CFM. With that low of a flow, I would stick with the air stones. A diaphragm diffuser won't work for you because that many will need more air than your pump produces. With 9 airstones, you are only seeing 0.43 CFM at each airstone, which is not enough to operate a membrane diffuser.

The one system I built for a customer utilized a Gast 1023 rotary vane pump that produced 9.6 CFM @ 6' water depth. I used 3 coarse bubble rubber membrane diffusers for his "L" shaped pier. I'm guessing it was around 25' long and about 8' wide at the end. The pier is 48" wide.





One diffuser on each side of the end of the pier, and one directly under the pier about 10' away from shore in about 18" water. The compressor was just to the left of the pier in that dog house, and the air lines were 0.6" ID. This was an experiment for the winter to make sure that the system that we spec'd out would work before he purchased it. Typically the ice wouldn't be thawed that far along the shore on both sides of the pier, but that was in March when we had a warm spell when the air temp was in the low 30's during the day and low to med 20's at night. His pier goes directly South when it goes out in the lake and that previous week we had winds from both the East and West, so the waves melted the ice to the East and West of the pier more than usual. Typically it would be ice free about 10'-15' to the sides and end of the pier.

Thank you for the detailed information, I appreciate it and will look into what you are suggesting.

We've had triple digit heat indices her local for the last month, have had very little if any icing problems recently, here locally.
Actually Im surprised if my pond will ever cool down enough to get ice on it for a long time!

But I digress, it'll probably be here before we know it!