Ultimate Guide to Filling Dog Agility Tunnel Bags

09 Jun 2022Steve Schwarz

This blog post has my updated suggestions for filling your tunnel bags.

Ten years ago I wrote a blog post on filling tunnel bags that had some good info that I still follow:

  • Use gravel instead of sand. It won’t absorb so much water and is less likely to turn into a solid lump.

  • Put your gravel into small bags and not directly into the tunnel bags in case you need to remove them and so the gravel won’t leak out if the outer bag is torn/punctured.

Opening some of my 10 year old tunnel bags showed the plastic carrier bags I used then had started to break down. I also had some containing zip lock bags of gravel, but, after much tossing around the zip lock had come “unlocked” and gravel had spilled out into the tunnel bags.

This article addresses those shortcomings and gives step by step instructions.


I read somewhere that you want your tunnel bags to weigh up to 30-35 lbs each. It turns out, 0.5 cubic foot pea pebble bags at US home improvement stores weigh just under 50 lbs. So if you divide the gravel between a pair of tunnel bags they’ll each weight around 25 lbs.

I’ve found a one gallon zip lock bag holds about 8-9 lbs of gravel.

You could add a 4th zip lock full of gravel to each tunnel bag to add another 8-9 lbs of weight if you find 25 lbs isn’t enough weight. I’m using Jenny saddle bag tunnel bags and so far 25 lbs each is fine.

Here are the supplies you’ll need to fill a pair of tunnel bags:

  • One 0.5 cu ft bag of pea gravel.
  • 6 one gallon zip lock type storage bags.
  • Heavy duty packing tape (to keep the zip locks from coming unlocked with handling).
  • A scoop, shovel, or cup to move the gravel from the big bag into the storage bags.
Tunnel bag filling supplies
Tunnel bag filling supplies

Filling the bags

The gallon size zip lock bags to hold about 8-9 lbs of gravel with enough room to fold the top of the bag over twice after sealing. That was about 5 scoops with the cup I used to measure out the gravel.

The easiest way to work is to take out 6 zip lock bags and use your scoop/cup to add a scoop to each bag until you empty a bag of gravel. You can shift a little from zip lock to zip lock at the end to even them out if you are obsessive. LOL!

Gravel distributed across six zip lock bags
Gravel distributed across six zip lock bags

Then I squeeze the air out before sealing each bag, so they won’t pop open when bags are thrown around.

I folded the tops over twice and then used Gorilla packing tape to further seal the top of each zip lock bag.

Zip lock bags taped closed
Zip lock bags taped closed

When you put the zip lock bags in your tunnel bags you want the weight low in the bags so the bag keeps the tunnel from moving but the straps still flex as the dog banks on the sides of the tunnel.

For my bags the 3 zip lock bags fit perfectly side by side in each tunnel bag.

Three bags in place
Three bags in place

Depending on your tunnel bag zipper/velcro you might be able to leave half the gravel in the original bag and put the whole bag in one of the tunnel bags.

Have fun filling up your tunnel bags!

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