Changing substrate in a planted aquarium

[Gomisan]

My aquarium is doing well, but I think I've made the wrong initial choice with my substrate, I used a rather coarse pebble mixture, which while it looks great, isn't giving my plants much to hold onto, and the pebbles are a bit big for my loach to move about.

I am wondering how a change of substrate might be accomplished in an established tank.

I need to know practical things, like:

Should it even be done?
How to remove the old gravel?
How to add the new?
All at once or section by section?

I don't have another tank, so nowhere for the fish or plants to go. So if it's not a wise thing to do, I won't even consider it. But if a finer substrate will considerably help my plants and can be achieved without undue fish stress i'd like to try it.

I am thinking along the lines of the following

1) prepare and rinse new substrate
2) keep new substrate in a bucket of water taken from tank during water changes
3) during the next 4 water changes, remove 1/4 of the existing gravel in strips along the tank, and replace with new

I'd use a cup or something with the new gravel, so I fill the strips without just dumping it in.

comments? suggestions?

EDIT: I read in another thread a suggestion to have the new substrate in the tank in a nylon bag for a while to build up bacteria, this sounds sensible... any more thoughts?

 

[marks69]

if you change the whole thing at once you'll need to put some old gravel in a bag.just use gravel from the top, shove it in a nylon and leave it for a few weeks. i changed from pfs to flourite, and did it all at once, i just moved all the plants to a bucket, moved about 1/2 the fish, took out 1/2 the water and changed out.
put it all back and was good to go.

 

[Lauren]

uh, gravel changes, I've done a few of those. I think you have a good plan, time consuming, but good. Your fish won't like you, you are going to stir up quite a bit of nastiness into your water. Vacuum the gravel to be removed extra good before removing it.

I've done them in one fell swoop before. I got a bucket, filled it up with tank water, put all of my fish and plants in there, then I drained the tank, scooped out the gravel, replaced the gravel, put the water back in, replanted, and put my fish back. Because most of your bacteria is in your filter anyways, its safe to do. Also, it is nearly impossible to remove all of the gravel, I usually left a thin layer of the old stuff at the bottom to help jumpstart the bacteria in the new gravel. Might be less stressful for the fish, since they don't have to breath a heavy concentration of their own waste until your filter cycles through.

 

[Emg]

I can help ya Gomisan....I did that in a 29 planted a few months ago.

I used a 10 gallon tank to put all the fish in during the process. I added water from the tank into the 10 with the fish. I also hung the filter on that tank as well, just to keep it running....and stuck the heater in there too. I had the tank sitting on the floor next to the 29 while I did all this.

I filled a bucket with tank water and put all the plants in there...being careful when I uprooted them.

Then I took all the water and gravel out of the 29 and wiped and cleaned the sides all down really good...had the opportunity to get in there good, so ran with it. I used echo-complete for planted tanks as the new substrate. That stuff is great for planted tanks...you don't have to rinse it at all and it comes with some bio-stuff in it to help get a cycle going, along with lots of nutrients for the plants. Since you have a seeded/running filter with lots of bio in it already...cycling wont' be too much of a concern....so I didn't worry over much about that. Just don't change your filter pad for awhile after you do this.

PUt a bowl in the bottom of the tank so that when you fill it it doesn't slosh the substrate all around. When it's about half full, you can add your plants and decorations. I used this opportunity to trim the roots and dead old leaves off my plants before putting them all back in. Cleaned em all up nice.

After your plants and rocks/wood/whatever is back in.....finish filling the tank and acclimate your fish to the new water just like you would if they were new from the lfs. Make sure the temps are close...I warmed the water from my tap when I did the refill...adding dechlorinator of course. You could set aside some of the tank water you take out if you have something to put it in...I didn't so I just dumped it all but what was in the 10 with the fish. I didn't add that water back into my tank when I refilled it.

Keep an eye on the parameters for awhile and just do water changes as needed until it all settles in. Mark's idea about a nylon bag with some old gravel in it is a good one......easy to do if you can stand looking at it for awhile....lol...

 

[Gomisan]

Thanks for the advice and such. I've begun the process and will use this thread to log what happens and how I achieve it, for the benifit of others who may want to do the same later.

Last night I thoroughly washed the new gravel, and put what i hope is 1/4 to 1/3 of a tanks worth into an old nylon stocking (thoroughly rinsed to remove any detergents that may have been left from last wash). I've hung the stocking full of gravel in the tank to build up some bacteria, really not sure how long this will take, so I'm planning on 2 days.

The fish weren't crazy about the addition, and even with the lengthy washing of the gravel it still clouded the tank a bit, but I turned of the lights and gave them some peace & quiet and today they seem happy enough.

I'm going to make a small plastic divider for the tank, to keep the old & new substrates seperated as I progress.

 

[Gomisan]

Update.

Today I changed the first section. I can see why doing it all at once looks like such a good idea now. Even after vacuuming that section of gravel, the muck stirred up in the tank was disgusting!

I'll probably try and do all the rest at once next week. For now, I've done a water change and popped a towel over the tank so the fish can settle down for a bit.

 

[asincero]

I'm thinking of doing a substrate change out myself. The reason being was that I read the kind of substrate I'm using isn't ideal for the plants I have in the tank. Apparently, I'm using gravel that is too big. The plants I have, Amazon Swords, like gravel thats finer.

My plan of attack is to set up another tank, throw the fish and plants in there and do the change out all at once. I don't have a lot of fish now, since most of them has died . I have 4 mollies and 2 guppies left. I can probably keep them in the secondary tank indefinately, so I can take my sweet time in doing the substrate change.

Since I read most of the nitrogen cycle bacteria live in the filter, I suppose I can consider the tank already cycled after doing the substrate change? I should probably dose it with some ammonia and see if the ammonia disappears after 24 hours before I put everybody back in?

 

[Gomisan]

I wouldn't dose it with ammonia. Simply add the fish back slowly and watch the ammonia levels, they should stay OK. If it starts to show up, don;t add any more fish until it drops.

It's a planted tank, so the plants will be helping take care of any mini-cycle that may happen.