Easiest way to switch from gravel to sand

Sorry, I know there's a lot out there about this, but what's the easiest way to switch from sand to gravel while keeping as much BB as possible? I read that someone put their old gravel into nylons for a little bit, to let the BB multiply onto the new sand. Would this work and are there any better ways?

 

I'm sure that would work, but if you have a matured filter and you reuse existing tank water after you replace the substrate, your cycle shouldn't suffer. I've never really thought about it, but becasue sand packs so densely I actually don't imagine it supports much BB anyway. Gravel has a lot of spaces and surface area, but really I think the only part of the sand that's getting significant oxygen is the top.

 

If you have an established tank your filter media should have enough BB to support the change. Just scoop it out and change it out There is not nearly as much BB in the gravel as there is in the filter

 

Can you do half and half, one on each side, until the BB has grown on the sand and then you remove the gravel ?

 

Swapped from gravel to sand several years ago. I removed gravel and 50% of water. Added sand and never looked back.

 

How you do it depends on how strong your cycle is. If this is a brand new cycle you may experience a mini-cycle but if the tank is well established with sufficent media in your fitler and lots of decor your cycle should be fine. You will be removing some bacteria but what you are removing should be replace fairly quick, I would think within just a few hours.

My tank has been cycled for 3 and 1/5 months, give or take. Also, should I take my fish out when I put the sand in?

When I switched from gravel to sand I didn't remove the fish but do what you are most comfortable with. I did make sure the sand was rinsed really really well before starting the process. You want to be sure the water is running as clear as possible before putting the sand in the tank or you may end up with some very dirty tank water. It is so much easier to clean it well outside the tank. I used a plastic lawn cart for mine but a 5 gallon bucket will work well. Just keep adding water, stirring and pouring the water off until the water you are pouring off is clean and clear.

Keep the gravel and decor wet once pulled from the tank. It's not a bad idea to put some of the gravel in media bags. Put the bags where the water coming from your filter is running over and through the gravel. You will want to turn your filter off once you start adding sand. You don't want any of it pulled into the impeller. The sand will damage it. If you are running a HOB filter make sure the uptake tube is no less than 3 inches from the top of the sand to prevent it being sucked up into it.

 

My tank has been cycled for 3 and 1/5 months, give or take. Also, should I take my fish out when I put the sand in?

 

Remove the fish. I didnt and released anaerobic pockets in my gravel that almost killed my fish. Big mistake.

 

Remove the fish. I didnt and released anaerobic pockets in my gravel that almost killed my fish. Big mistake.

Good point. That could pose a problem in a well established tank with a deep gravel bed. In my case my gravel was only 1 inch or so deep and had been gravel vac'ed weekly so not much chance of a buildup of gasses.

 

Alright thanks! Should I remove my fish while i let the sand settle?

 

Alright thanks! Should I remove my fish while i let the sand settle?

I did. I was afraid all the sand dispersed in the water would irritate their gills.

 

Thanks everyone! I've got the sand coming in the mail. My plan is to take 50%ish water out into a bucket, remove my hiding decor (so it doesn't get filled with sand) and then put my fish in the bucket. After which I'll net my fish, remove the gravel, and add the sand.

 

With a finer sand I probably would remove the fish. If you're just switching to a finer gravel you're probably okay.

 

Keep it simple and easy.
Clean the new sand first.
Turn off filter.
Remove old substrate.
Put in new sand.
Start filter.
Dont worry about saving the old substrate for bacteria. There is enough bacteria in your filter media.
Do not remove fish.
Too stressful trying to catch them, then catching them, to put them back.
Also one less thing you have to worry about.

 

Good point. That could pose a problem in a well established tank with a deep gravel bed. In my case my gravel was only 1 inch or so deep and had been gravel vac'ed weekly so not much chance of a buildup of gasses.

Yep I didnt see that it was fairly new. Mine was almost 2 inches and 3 yrs

 

If you have an established tank your filter media should have enough BB to support the change. Just scoop it out and change it out There is not nearly as much BB in the gravel as there is in the filter

Agreed. Did this before. Tank was well established, and had zero problems doing it.