Should I Replace Gravel with Sand?

[WhistlingBadger]

That’s usually not a good idea. There’s a lot of bad critters and microorganisms.

Itiwhetu said that sand didn't naturally occur in rivers. I was saying that, in some cases at least, it does. Some experts do recommend taking substrates from natural water bodies that (this is important) don't have fish, such as spring-fed ponds that don't connect to fishy waterways. If there are no fish in the water, there are unlikely to be fish pathogens, but there are likely to be beneficial critters. I wouldn't really recommend it, but I'm sort of intrigued by the idea.

 

[itiwhetu]

I have always taken my substrate from natural sources. Either lakes or rivers

 

[PheonixKingZ]

Itiwhetu said that sand didn't naturally occur in rivers. I was saying that, in some cases at least, it does. Some experts do recommend taking substrates from natural water bodies that (this is important) don't have fish, such as spring-fed ponds that don't connect to fishy waterways. If there are no fish in the water, there are unlikely to be fish pathogens, but there are likely to be beneficial critters. I wouldn't really recommend it, but I'm sort of intrigued by the idea.

Sand totally does exist in natural rivers. I walk in it every time I go wade. ?

 

[itiwhetu]

I didn't say it didn't exist, what I was trying to point out is that the sand or fine gravel in rivers is much coarser than play sand, and that if play sand compacts in aquariums it is not good. Plants will have difficulty getting their roots to grow through it. With play sand there will also be no water movement and therefore dead spots will occur in the aquarium. That is why a coarser sand or fine gravel is preferable over something that is very fine like play sand.

 

[JennCav]

My 170L tank (recently learned that it's a discontinued model - a Juwel Panoramic - for anyone wondering) has a sharp-ish gravel as its substrate and an area to the right with smooth pebbles. As some of you know I keep kuhli loaches, corys and plecos* in this tank, which I'm aware need sand rather than gravel to properly thrive. I'm starting to get increasingly worried about damaging their undersides, and I'm hoping to get some more catfish in the future so I'd like to make the newcomers as comfortable as possible. Is it too late to switch out my gravel for sand?

Any advice and/or recommendations would be very helpful!

And... In the mean time, would it be worth moving these fish to my 54L that already has sand? It's currently quarantining three female guppies and two upside down catfish, but once the quarantine is up I'd probably be able to move them in.

*2x plecos (one sailfin and one common that will be rehomed soon)
6x corydoras aeneus (3x albino 3x bronze)
3x kuhli loaches (getting more when I have the space + money)

I went through the same thing when I first started my 20G. I think you should change to sand but keep some of the old substrate in tank for a bit, like in a glass dish or something bc I ended up having to start cycle all over again. And make sure not replace the old filter at this time. I learned the hard way.

 

[PheonixKingZ]

I went through the same thing when I first started my 20G. I think you should change to sand but keep some of the old substrate in tank for a bit, like in a glass dish or something bc I ended up having to start cycle all over again. And make sure not replace the old filter at this time. I learned the hard way.

As long as @PlasticGalaxy keeps the same filter and filter media, then he shouldn’t loose his cycle.

I do agree that sand/substrate in general holds lots of beneficial bacteria, but performing a substrate change shouldn’t effect his cycle.

 

[JennCav]

Oh okay, that’s good.

 

[PlasticGalaxy]

I went through the same thing when I first started my 20G. I think you should change to sand but keep some of the old substrate in tank for a bit, like in a glass dish or something bc I ended up having to start cycle all over again. And make sure not replace the old filter at this time. I learned the hard way.

As long as @PlasticGalaxy keeps the same filter and filter media, then he shouldn’t loose his cycle.

I do agree that sand/substrate in general holds lots of beneficial bacteria, but performing a substrate change shouldn’t effect his cycle.

Oh okay, that’s good.

Yep, as Pheonix said, I've got my external filter for this tank that's been running since I set the tank up. That and all the plants, decor and other bits are going back in... Hopefully it'll be alright.

 

[PheonixKingZ]

Should be. I would wait 24 hours before adding the fish back in, so it gives the tank a little while to settle back in.

 

[PlasticGalaxy]

Should be. I would wait 24 hours before adding the fish back in, so it gives the tank a little while to settle back in.

I wonder where I could put them all overnight... The plan was to just keep them in a bucket while I did the sand. The 54L would work, but doesn't have a lid and my plec and corys are prone to jumping... Not to mention that scary shrimp of mine.

 

[Byron]

I wonder where I could put them all overnight... The plan was to just keep them in a bucket while I did the sand. The 54L would work, but doesn't have a lid and my plec and corys are prone to jumping... Not to mention that scary shrimp of mine.

I have changed all my tanks from gravel to sand (happened to use Quikrete Play Sand which is ideal and available in NA) about 8-9 years ago now. Wished I had done it much earlier, and never looked back. But, changing the substrate is a major upheaval and should not be done with fish left in the tank. I know, some do it, but that does not remove the risks and we have had members here who lost fish by leaving them inn. Someone mentioned anaerobic spots in the substrate--this is applicable to any substrate depending upon depth but also decor like chunks of wood, rock, or ornaments left in the same spot and then disturbed.

I always use a spare tank with some sand in the bottom, held in the cupboard for such work, it does not need to be as large as the display tank. Fill it with water syphoned from near the top of the display tank. Move the filter and heater over undisturbed (if much smaller a tank, be sure the heater will not overheat the smaller space). Move over some of the decor to provide shelter for the fish. Plants can be left floating. This provides plenty of time to do the job, and it means you can net the fish back in the morning rather than evening, which allows them to settle much better. Have a cover on the tank, it is amazing how fish will often jump, even cories will be on the floor. The completed display tank can be filled with fresh water, dechlorinated obviously, provided the parameters (GH, pH and temp) are reasonably the same to those of the temp tank.

To clear up an earlier point...the substrate once established is the prime bed for bacteria in the aquarium. More important than the filter, which you can (or should be able to) do without, other than for water circulation--but not the substrate. Not just nitrifying bacteria, but even more important bacteria, aerobic and anaerobic, both are essential for a healthy system. Anaerobic areas likely occur under wood, rock, etc, so leave them alone during water changes if you do want to vacuum over the open areas of substrate. Never dig under these areas. The fortunate thing is that the substrate bacteria bed will re-establish, and its temporary loss will not harm the fish. Another note, with live plants you should have no nitrifying issues anyway; plants can take up a surprising amount of ammonia/ammonium, and they outcompete the bacteria in the filter doing so in most tanks.

 

[itiwhetu]

I have changed all my tanks from gravel to sand (happened to use Quikrete Play Sand which is ideal and available in NA) about 8-9 years ago now. Wished I had done it much earlier, and never looked back. But, changing the substrate is a major upheaval and should not be done with fish left in the tank. I know, some do it, but that does not remove the risks and we have had members here who lost fish by leaving them inn. Someone mentioned anaerobic spots in the substrate--this is applicable to any substrate depending upon depth but also decor like chunks of wood, rock, or ornaments left in the same spot and then disturbed.

I always use a spare tank with some sand in the bottom, held in the cupboard for such work, it does not need to be as large as the display tank. Fill it with water syphoned from near the top of the display tank. Move the filter and heater over undisturbed (if much smaller a tank, be sure the heater will not overheat the smaller space). Move over some of the decor to provide shelter for the fish. Plants can be left floating. This provides plenty of time to do the job, and it means you can net the fish back in the morning rather than evening, which allows them to settle much better. Have a cover on the tank, it is amazing how fish will often jump, even cories will be on the floor. The completed display tank can be filled with fresh water, dechlorinated obviously, provided the parameters (GH, pH and temp) are reasonably the same to those of the temp tank.

To clear up an earlier point...the substrate once established is the prime bed for bacteria in the aquarium. More important than the filter, which you can (or should be able to) do without, other than for water circulation--but not the substrate. Not just nitrifying bacteria, but even more important bacteria, aerobic and anaerobic, both are essential for a healthy system. Anaerobic areas likely occur under wood, rock, etc, so leave them alone during water changes if you do want to vacuum over the open areas of substrate. Never dig under these areas. The fortunate thing is that the substrate bacteria bed will re-establish, and its temporary loss will not harm the fish. Another note, with live plants you should have no nitrifying issues anyway; plants can take up a surprising amount of ammonia/ammonium, and they outcompete the bacteria in the filter doing so in most tanks.

Byron do you vacuum the bases of your tanks or do you leave them undisturbed. I have always left my bases undisturbed and have never used a vacuum to clean the base.

 

[PlasticGalaxy]

I have changed all my tanks from gravel to sand (happened to use Quikrete Play Sand which is ideal and available in NA) about 8-9 years ago now. Wished I had done it much earlier, and never looked back. But, changing the substrate is a major upheaval and should not be done with fish left in the tank. I know, some do it, but that does not remove the risks and we have had members here who lost fish by leaving them inn. Someone mentioned anaerobic spots in the substrate--this is applicable to any substrate depending upon depth but also decor like chunks of wood, rock, or ornaments left in the same spot and then disturbed.

I always use a spare tank with some sand in the bottom, held in the cupboard for such work, it does not need to be as large as the display tank. Fill it with water syphoned from near the top of the display tank. Move the filter and heater over undisturbed (if much smaller a tank, be sure the heater will not overheat the smaller space). Move over some of the decor to provide shelter for the fish. Plants can be left floating. This provides plenty of time to do the job, and it means you can net the fish back in the morning rather than evening, which allows them to settle much better. Have a cover on the tank, it is amazing how fish will often jump, even cories will be on the floor. The completed display tank can be filled with fresh water, dechlorinated obviously, provided the parameters (GH, pH and temp) are reasonably the same to those of the temp tank.

To clear up an earlier point...the substrate once established is the prime bed for bacteria in the aquarium. More important than the filter, which you can (or should be able to) do without, other than for water circulation--but not the substrate. Not just nitrifying bacteria, but even more important bacteria, aerobic and anaerobic, both are essential for a healthy system. Anaerobic areas likely occur under wood, rock, etc, so leave them alone during water changes if you do want to vacuum over the open areas of substrate. Never dig under these areas. The fortunate thing is that the substrate bacteria bed will re-establish, and its temporary loss will not harm the fish. Another note, with live plants you should have no nitrifying issues anyway; plants can take up a surprising amount of ammonia/ammonium, and they outcompete the bacteria in the filter doing so in most tanks.

Do you think I should add the fish from my display (170L) tank to my smaller (54L) tank while I wait? If I keep them in a bucket overnight I'm pretty sure they'd freeze or jump out, but the 54L has some fish already in it and hasn't been set up for nearly as long as the 170L. So much indecision!

 

[Byron]

Byron do you vacuum the bases of your tanks or do you leave them undisturbed. I have always left my bases undisturbed and have never used a vacuum to clean the base.

Same here most tanks. My group of some 40 Corydoras never have the sand touched. Another tank with very few fish now seems to accumulate a lot of organic matter from the dried leaves and wood primarily, so I run the W/C over the open areas to get this out. But I agree, substrates once established are usually self-sustaining, obviously provided the tank's biological system is in balance to start with--some people overstock their tanks and this can suddenly break down. And live plants, even just floating, always help the system.

 

[Byron]

Do you think I should add the fish from my display (170L) tank to my smaller (54L) tank while I wait? If I keep them in a bucket overnight I'm pretty sure they'd freeze or jump out, but the 54L has some fish already in it and hasn't been set up for nearly as long as the 170L. So much indecision!

I would never keep fish in a bucket overnight. A temp lowering will almost inevitably cause trouble, adding that stress on top of the bucket/netting stress. This often results in ich. If the other tank is running with fish as I am assuming, and the fish are compatible with the others, that would be an option. Catching them again might be tiresome though.