All Pond Vacuums on the market under $800 say they can't suck leaves up, have shoddy reviews and just don't have suction power for 4+ ft deep. We tried the shop vac DIY pond vacuum and it sucks. It has to be drained every 20 seconds, doesn't have enough suction, and just doesn't work at all for our 5 ft deep 2500 gallon pond.
In comes the 2" Semi-Trash Pump from Harbor Freight! This thing sucks hard, and cleans up fast! It won't break down on you, shut off every 30 seconds to drain, and also helps with large ponds to do a quick water change! Take note, at full speed this thing can move up to 158 gallons a minute at full blast but we ran it at about half speed and using the smaller 1-1/4" PVC helped to suck up less water while still doing a perfect job cleaning everything. It even had more than enough suction to fully clean our bottom drain out!
All you need is:
• 2" Harbor Freight Semi-Trash Pump
• 2" Non collapsible intake hose
• 2" discharge hose
• 1-1/4" PVC pipe
You can get everything but the PVC pipe form HF and should all cost under $400, especially if you wait for a sale or use a coupon. All hoses from HF will include the hose clamps and fittings to attach to the pump so no worry about grabbing extra hardware!
I couldn't find any info if this Trash Pump could handle leaves but turns out it does, especially if they're leaves that have been in the pond decaying all winter. New leaves might clog it up but in that case, you just unbolt the 4 intake port bolts and clean out the stems (with the engine off of course lol). Make sure you don't run the motor without water as you can burn up the pump pretty quickly. Just keep an eye or have a friend help watch the discharge hose.
We discharged the water and debris into our yard. We took advantage of this and used it to drain 20-40% of the 2500 gallon pond and did the first water change of the year. Just make sure when refilling the pond to use dechlorinator as you refill. Local pond shops will have super concentrated dechlorinator for use in large ponds. The dechlorinator at pet stores is generally only meant for small 100-300 gallon ponds.
You could drain the water back into the pond with a mesh debris bag over the output hose but most of the leaves will get churned up into particulates and wont get caught by the mesh bag. This would result in cloudy water and continue to provide nutrients to the algae we all want to get rid of.
Hope this helps and please comment below with any questions!