Backyard Aquaponics
A place to discuss aquaponics

My submersible pump had been in action for about 4 years. Never ran dry. I believe it is a 4000 liter per hour and it's pushing about 1 meter vertically to the filter. Don't remember what kind of pump it is. Seems to get weaker. Have cleaned the inside of the pump a number of times. Take out the organic material and muck. Gets slightly better and then within a few days is barely pushing any water. Any suggestions?

Is there build up in any of the lines after the pump?

electric motors can get "tired" but I'd be checking all your pipes for a buildup of something.

We do get lots of calcium build up. Will check.

I switched out the pipes from the pump to the filter and from the filter to the pond. I also raised the level of the filter and the flow is better. Thanks for the advice.

Sounds like you've got it sorted, but another point worth considering is pump impellors can also wear out slowly over time. They are considered a consumable item, which is why most pump manufacturers don't cover impellors in their pump warranties

My son spent some time observing the flow yesterday and says that the flow is very erratic. Gets very strong and then tapers off. Will loose the flow completely. All the pipes are new and clear. If the impeller is worn out is there anything to do or is it time for a new pump?

i had a small 700l/hr pump. low voltage ac and part of the coil has burned out. this i could hear though sounding like it was missing a beat.

an earlier submersible pump that i got had a problem where water would get into the electronics/motor part of the pump and because it was a DC pump, the positive terminal eventually corroded off. don't buy the cheap dc submersible pumps from china. the ones with the electrical parts sealed by epoxy to be 100% waterproof are the best.

me and my dad had actually pulled the dc bilge pump and modified it to be an out of water inline pump with 25mm in and out fittings. don't use it for the current system though. it's 70L per min and my whole system is probably less than 400L.

erratic pumping can be damage to the motor. can you tell us more about the type of pump?

Take it to a shop and show it to them, they might be able to change a small part or two like the impeller or something and give it some more go. A good aquarium shop usually has a small back shop which deals in repairs and what not.

Otherwise it might be time to replace it altogether. If all pipes and all are clean and there is no new gunk source in the tank that has been getting in and clogging it then it may have seen the end of it's days.

Cause might be a failing capacitor, the old pumps you could fix the new ones are encased in epoxy so no real hope.

Took it to the store where I bought it and they don't have parts for that model. I think he said it was a Jeba, from China. I guess 5 years is not bad. Now the question of what to replace it with.

The pump sits in a 700 liter koi pond. Has about 20 fish in it, not too big. I am building a GB on the wall that is next to the pond. The main goal is to get the water more clean. Currently I run the water through a Tetra barrel filter. Has some of that synthetic cotton and those honeycomb plastic pieces. I don't clean it often enough.
The height that the water will need to go up to is about 180 cm. I think I plan on splitting the flow of the water from the pump and have part of the flow come over the waterfall constantly for air and the beauty. The rest of the water will go through the GB and the siphon will drop it back to the waterfall or some other affect that will get the water to the pond.
Questions:
What size pump should I get for that much lift? Keep in mind 1/2 to the waterfall and half to the GB. Or could be 30/70.
What volume of water needs to be running through the GB to get the siphon working well?
Should I put the Tetra filter in line after the GB or before?
Here's a picture of where the system will be set up.

Flow throw GB: Since the pond is 700 litres you should try to get at least 700 litres per hour. You can size a pump easily as you know the height, the store can show you as well as the pump literature or box a power curve. pick the pump that shows about 1000 LPH so you can have flow for the waterfall too.

Tetra filter: I think put it in line before the GB so that the solids don't clog it over time as well as give a place for the solids to mineralize and thereby put more useful nutrient in the system.

Did the store tell you what part you needed? You might be able to use the same from some other pump if the sizing matches or order it online. Five years isn't bad though, depends on what you paid for the pump.