Replacing substrate

[roydooms]

How can you successfully replace your substrate in your current tank without killing any fish or causing your tank to cycle again? I'm planning to replace my regular substrate with ones that are meant for plants. Anyone has experience with this? How did you do it? Did you take all the fish out? Is it a good idea to just put it on top of the old substrate? Thanks.

 

[Fishguy2727]

Effectively all of your nitrifying bacteria are in yoru filters, not your substrate or anywhere else in the tank. Just vacuum your current substrate really well two days in a row. Right after the second time, while the water is still low, turn off the filters and scoop out all the substrate. Then put in the new stuff, make sure it is all settled, refill the tank, and turn the filters back on.

 

[roydooms]

Effectively all of your nitrifying bacteria are in yoru filters, not your substrate or anywhere else in the tank. Just vacuum your current substrate really well two days in a row. Right after the second time, while the water is still low, turn off the filters and scoop out all the substrate. Then put in the new stuff, make sure it is all settled, refill the tank, and turn the filters back on.

I was thinking if "successfully" is the right word but it's "effectively" thanks.

Anyway, how about the fish and plants? Do I uproot all the plants? Put all the fish in a separate container/bag with the same species? Thanks.

 

[Homedog98]

Umm... I'll have to respectfully disagree with fishguy. While about 50-75 percent of your bacteria IS in your filter, the 50-25 percent that's left is in the substrate. None is in the water though. I'd put it over the old stuff, and just move the fish into a QT until everything settles, then add fish a few at a time to keep from mini cycling. As for the plants, uproot and put in qt with fish. Bags work for fish too, but take more work.

 

[roydooms]

Umm... I'll have to respectfully disagree. While about 50-75 percent of your bacteria IS in your filter, the 50-25 percent that's left is in the substrate. None is in the water though. I'd put it over the old stuff, and just move the fish into a QT until everything settles, then add fish a few at a time to keep from mini cycling.

My concern about this is if you put the new one on top, it'll mix together when you vacuum/clean it and that not going to be a good sight. Plus the ones that I have now is about 1/4-3/4 and the one that I want to replace it with are small. Eventually, when you clean it, the smaller substrate will end up at the bottom. And it'll look like what it was before.

 

[Homedog98]

Ooh! Just got an idea! Put some of the old substrate in some pantyhose and clip it to the side of the tank. Take out the rest and do whatever. Do the same listed above with fish and plants. Put in the new stuff, and leave the pantyhose in until you get steady readings. Then put in fish a few at a time. Geez! Why couldn't I think of that before!!!

 

[roydooms]

Ooh! Just got an idea! Put some of the old substrate in some pantyhose and clip it to the side of the tank. Take out the rest and do whatever. Do the same listed above with fish and plants. Put in the new stuff, and leave the pantyhose in until you get steady readings. Then put in fish a few at a time. Geez! Why couldn't I think of that before!!!

I don't have have to clip the pantyhose on the side. As long as it's in the tank it'll be ok. This is going to be a long day. I'll wait until my discus gets a little comfortable. I just added them a few days ago and they're are still a little shy/stress. I might put the fish in a big styrofoam box with heater and air pump. I put the heater inside the gravel vac tube(not the hose) to prevent any accident. Good idea. Thanks.

 

[roydooms]

I just bought a 55g with stand for $30. I'm thinking of putting all the fish in there while I'm replacing the substrate. That's going to be a lot easier than putting fish in a bucket/bag. I'll drain the water and put some in the 55g then back in the 125g.

 

[Mr. Limpet]

I just bought a 55g with stand for $30. I'm thinking of putting all the fish in there while I'm replacing the substrate. That's going to be a lot easier than putting fish in a bucket/bag. I'll drain the water and put some in the 55g then back in the 125g.

Without sturring the gravel move water, filters, ets to the other tank and you're fully cycled. Then you can redo the gravel and what not in your big tank.

 

[roydooms]

Without sturring the gravel move water, filters, ets to the other tank and you're fully cycled. Then you can redo the gravel and what not in your big tank.

Yup, that's actually my the plan. That's why I want to keep my 2 HOB even when I got a canister filter so I can use it to put in a new tank to help with the cycle or it will instantly cycle the tank.

Edit: I will also put some of the old substrate in the 55g. After I'm done and returned all the plants and fish in the 125g I will use the 55g as a QT(finally have one)

 

[Fishguy2727]

Homedog: Where are you getting your numbers that 50-75% are in the filter and the rest are in the substrate?

Bacteria live where it is best for them. That means where they get the most oxygen, food (ammonia and nitrite), and the best temp. The temp is uniform in our tanks so that doesn't alter where they will live in our tanks. So where will they get the most oxygen and food? Where there is the most flow, which is in our fitlers and not in the substrate.

You can move the fish and filter and nothing else and instantly cycle a new tank. This wouldn't be so if a significant amount of bacteria are in the substrate. However, you can't move the substrate and the fish and not the filter without having to re-cycle, which wouldn't be true if a significant amount of bacteria were in the substrate.

If you are pulling out all the substrate then just move the plants into a bucket. The fish can stay in during substrate changes.

 

[Homedog98]

Homedog: Where are you getting your numbers that 50-75% are in the filter and the rest are in the substrate?

Bacteria live where it is best for them. That means where they get the most oxygen, food (ammonia and nitrite), and the best temp. The temp is uniform in our tanks so that doesn't alter where they will live in our tanks. So where will they get the most oxygen and food? Where there is the most flow, which is in our fitlers and not in the substrate.
.

I get my info based on the opinions I've formed after researching on this site, and experience. There is a fair amount of flow reaching the gravel, and certainly enough fish crap gets stuck in there to have an ammonia source. Check your water parameters before doing a gravel vac, then check them again. You'll notice your nitrates (if it's a cycled tank) will be noticeably lower then they were before. This is because some of the good bacteria in your substrate was sucked up! That's also why most people only vacuum one section of gravel at a time, partially is to keep from emptying your tank, and the other part is to keep from sucking up all that good bacteria in your gravel!

 

[roydooms]

I get my info based on the opinions I've formed after researching on this site, and experience. There is a fair amount of flow reaching the gravel, and certainly enough fish crap gets stuck in there to have an ammonia source. Check your water parameters before doing a gravel vac, then check them again. You'll notice your nitrates (if it's a cycled tank) will be noticeably lower then they were before. This is because some of the good bacteria in your substrate was sucked up! That's also why most people only vacuum one section of gravel at a time, partially is to keep from emptying your tank, and the other part is to keep from sucking up all that good bacteria in your gravel!

If that is the case then you should detect ammonia and nitrite. Less bacteria to process them as well. Right?

 

[Homedog98]

Yes. In other words, to much of a siphon causes a mini cycle.

 

[roydooms]

I also learned from this site that a fair amount of essential bacteria lives in the substrate but not that much.

 

[Homedog98]

I also learned from this site that a fair amount of essential bacteria lives in the substrate but not that much.

Ya... Those #s where a bit vague... But it still has quite a bit of effect.

 

[roydooms]

Yes.

Causing a mini cycle? But that is not always the case. Sometimes you get lucky. But I bet if you replace all your substrate at the same time you'll experience a mini cycle.

 

[Homedog98]

Ya. That's pretty much my point.

 

[Gargoyle]

Beneficial bacteria does in fact reside everywhere in the tank. The highest concentration is in the filter(s) however. So hanging onto some of the old substrate is a good idea of your filter media housing the bacteria could be placed in danger. But if you have a huge filter as most do, then putting the old filter on the new tank should result in an instant cycle. The old water doesn't need to be transferred over or anything as no bacteria will be there. But it will be on or in ANY solid object in the tank in various quantities. The substrate is no exception to this. Just take care to preserve the bacteria in the filter and you should be just fine. If your nervous about it at all just don't clean any decorations with anything but used tank water before placing them in the new tank. In the end just do what makes you the most comfortable.

 

[trackfast]

Would it be possible to siphon out half the gravel and lay down the new substrate? I'm guessing you could leave it that way while the bacteria spends and then vacuum out the other half later ?