The water changes is well worth it alone and time saver. I don't use all the attachments but more than enough to help with any needs.

Let's start with this is a super strong water pump/vacuum. It moves water very, very fast. The cord is long, the neck is extendable... all good things. Personally, I only use 4 of the attachments (the hose, the shower with the bag on it, the gravel tube, and the gravel tip) the other attachments just don't work for my situation. The issues I have with this is it's hard to maneuver when you're using the shower because you need to be aware of 'where' the shower head is or you will accidentally spray water on your floor.. (but that is mostly user error..lol) but the biggest issue is since the pump needs to always be under the water (so it doesn't burn out) I can never get enough of the water out of the tank. I guess that should have been obvious to me, but I never really thought about it until I was actually using it. The product itself is great and works like it says but I wound up using a manual siphon at the end of the day.

Bought to clean cold plunge tank and there not enough suction to even pick up pieces of carbon from the filter. Tried every attachment to try and pick up small bits of carbon media and would not pick them up. Not recommended unless suctioning the slightest of debris. Maybe enough to suck up algae once it's been scraped off?
Update: I was getting ready to throw in the trash and find another solution. Then I saw the valve on the outflow tube was using for the filter bag. I turned in 90 degrees and BAM!, all the suction I needed. I do not have the instructions anymore but do not recall any mention of the valve. It may be common place for many devices but I did not know what it was for. Now it makes the product even BETTER! Using the valve you can actually adjust the flow depending on what job you are doing. Decrease for filtering sand, increase for pure cleaning, etc.
Seller reached out proactively after my initial review to try and resolve the issue. Good customer service.
Great product, would now highly recommend for any of your cleaning needs.
Works wonderfully as a transfer pump as well. Used it to drain our cold plunge tank. Since I'm the garage, used the tube included and inserted into the end of a garden hose that went out to the yard. 200 gallons gone in no time.

This gravel vac has several configurations and different ways to use it. What I found most useful in my setups are the vacuum and pump attachments. There are some other attachments that would be best suited for a bare bottom tank (which I don't have).

Gravel Vac:
The gravel vac worked great on my substrate that is "pea gravel" but I didn't use it on my sand bedded tanks as the sand grains are too small and would get sucked up into the pump motor. If you have a gravel bed, this should work great for you to do a good vacuuming. There is a sponge inside the vacuum attachment however I found that it worked really well without it. The diameter of my old vac is a bit wider and I found that the Hygger vacuum fit in between rocks, driftwood, etc much better. Also, the bag that the vacuum discharges into tended to fall off after much use but a rubber band held it on great!

I also found that the pump attachment was very handy. It allows the handle to sit upright on a small base. I have emptied a 55g and a 29g tank - both extremely quickly and have also used it to speed up water changes. The included hose although long enough to reach a bucket, was not long enough to reach a drain however I found that my manual siphon hose attaches to the Hygger which allows me to reach my drains.

A few words of caution...
First, when you're done and remove it from the tank, regardless of which attachment you're using, be prepared to have a bucket close by to put it in as it will leak water out of it. I hold it above my tank to let it drain and then put it immediately into a bucket.

Second, if you're using this for water changes, remember the pump sits at the BOTTOM of the tank. It's really easy to empty your tank completely if you're not paying attention!

I've used a couple battery operated gravel vacs and I was never happy Witt their power. This one plugs into the wall and is much stronger!

Overall, this gravel vac works very well for my purposes in the fish room.

it's a pretty good tool ,with a bunch of adapters -extentions.
Pay attention to the instructions ,they are not good ,but you can figure it out with the pictures.
I used it to clean the tank (as a vacuum),
used the bag (without filters) to collect debris and algae ,I am very happy with it ,pocked up a lot of gank,way easier to clean the bag instead of having to take out my fluval filter and clean it again .
make sure the motor is submerged ,you don't want to let it run without water,you will fry it .

and use the extentions appropriately .for example ,there is a different extention for rocks-gravel and a different one for sand .