Moving Fish to a Larger Tank

In My Humble Opinion
1

I want to upgrade my 20gal tank to a larger one. I have a 20gal that is at slightly over 100% capacity based on the fish-inch per gallon rule. I change about 4 gallons of water a week, and the tank is doing well, with all the chemical parameters good, but I have live plants that I have to keep thinning, which I’d like to allow to grow more, and I worry about the fish not having enough room. Also, I have a loach that I got because I had nuisance snails (which is when I went over 100%), and he may grow another inch, plus, I’d like to add another loach, because I keep reading that it shouldn’t be a solitary fish.

It’s a tropical freshwater.

I have never moved fish, and I’m not really sure how to do it safely. I’m also not sure whether it’s better to have two 10-20 gal filters, or one 20-40. I already have two 10-20, because I keep a spare in addition to the one on the tank. I can see the advantage, if one broke while I was away, and they would be less likely to pull up a fish, which the stronger single filter could (I have some small danios), but I wonder if the 10-20 would circulate the water from the bottom of the tank, and I have corys in addition to the loach.

I have the same question about heaters: one or two?

I’m thinking that to move the fish, I can get a ten gallon tank (I can get a cheap one for $10, which probably isn’t a great tank, but I don’t need it to last long) and a five gallon bucket, in addition to the bucket I have when I change the water.

One problem I have is that the new tank will have to go where the current tank is.

I figure I get the tank stand put together, and ready to go, and have my extra substrate and decorations ready, then put the 10gal tank on a table near the current tank, and siphon water out until it’s full, then put a heater and filter on it, and net the fish into it, and leave it while I put the rest of the water into the buckets.

Once the water is out, I can move the tank and stands, and then pour the current substrate into the new tank, and add the new, and mix them, then arrange the decorations and move the plants. At that point, I can add the water from the buckets, and five gallons of new water. Then I’ll put in the heater and thermostat, and wait for the water to get to the same temperature as the water in the 10gal tank.

Once the temp is right, I’ll net the fish in, and add the water from the ten gallon tank. Then I can put on the filter. I thought for the first day, at least, I would put the current filter on, even if I have a larger, new filter on it, just because I have all the good bacteria on the current one.

I should probably add the other five gallons of new water, because the filter will need it. I can warm it a little by putting the jugs in the tub. It’s 1/4 of the water, but that shouldn’t be too much, if I have the old filter on the tank, so that I have the bacteria there.

Should I add tank starter or stabilizer? I usually add a little Prime when I change the water, even though I use bottled water-- there is ammonium (the non-harmful form) in my tap water; it doesn’t hurt the fish, but it gives me false high ammonia readings. I also add freshwater aquarium salts.

Does that sound like a workable plan? are there any alarm bells for people who have swapped aquariums (spellcheck flags “aquaria” :dubious:) themselves? I know it’s complicated, but I have the issue of needing to put the new one in exactly the same place. Also, the best time to do it is either when the boychik is at school, and the cats are shut in a bedroom, which means DH is at work, or when DH takes the boychik and the dog out. DH is better at handling the boychik and the dog at the same time, and he’s a little klutzy at things like netting fish, or not tripping over buckets of water, so even though he’s stronger when it comes to things like moving big objects, it’s probably better for me to do it. Plus, I’m the one who cares for the aquarium, and I’m not sure he can do everything alone. It may be that if we wait, we’ll have a chance to do it together, but all that really means is that we might not need the buckets.

2

My experience as an ex-aquarium keeper (I once had a 120, 75, 50, 30 and several smaller going in the same room, but an earthquake put a stop to all that), is that your main concerns are to keep the same temp and same chemical and bacterial balance as much as possible during the transition. You will need a heater for every tank your fish are in. Use as much water from the old tank in the new tank as you can.

If it was me? I would set up the 10 (much better: two 10s, if you have a lot of fish) a week beforehand, using your present aquarium water. Then move the fish into them, save the water of your present aquarium (and the unwashed filter), set up the new aquarium in its place, let the new tank cycle for a week, and then move your fish into their permanent digs. Much safer.

If you use some of your original substrate, same filter, and same water, there is no reason on earth to use tank starter.

I used to do this sort of thing all the dang time. I only needed help to lift the really big tanks into place, otherwise it was just me and my obsessive hobby.

3

How do I use the water from my tank in the 10gal, and also in the new tank? I have 20gal now, and want to set up a 30gal.

Should I set up the 10gal with like, 8gal from the current tank, and a heater and filter, and two fresh gallons, and then put 8gal into the current tank and let them both run a week, maybe use the old filter in the 10gal, and put the new filter on the current tank, then on moving day, put the fish into the 10gal, put the water from the 20gal into buckets, or a plastic tub, move the new tank into place, and then put all the substrate and plants into it, and move the water with the 5gal bucket, or with jugs, and bring it back up to temp (it won’t have been unheated very long, and the tank is only a few degrees above room temp anyway-- 78’F vs. 72’F)? Then I can net the fish into the 10gal, and put the water from the 10gal into the new tank, and set up the filter (that will have been used for a week).

I have a lot of fish, but they will not be in the 10gal for more than an hour this way, and it won’t be nearly as crowded as say, a pet store tank.

4

Have you already bought the 30? What kind of loach? How many danios? Canyou list your full bioload for us?

5

Ideally, I’d use some substrate and whatever rocks or decorations from your current tank in the new one, add water to the new one(s) and let it cycle and grow bacteria for a week.
Two filters and two heaters are always better, as you suggest.
Ulfreida gives you good advice.

Second hand stores often have aquariums, as do yard sales, for very low prices.

6

You are “seeding” the new water in the new tanks, with the old water. Use all your old water to help your fish transition, as best you can contrive.

Your challenge is that you can’t age-in your new tank because it goes where the old tank was. Like I said, you should create some kind of holding tank arrangement so the new tank can reach some equilibrium before you dump those fish into it.

Use the water from your 20 in your 10s. Then use the water from your 10s in your 30.

7

5 danios, ranging from 1" to 1.5"

4 corys all about 2", and none expected to get bigger.

4 guppies, 2 about 1.25" in body but with 1" tails, and 2 about 1", with .25" tails. I thought the smaller ones would get bigger, but maybe not. The bigger ones seem to still be growing their tails, but not their bodies.

1 yoyo loach (botia) about 1.25", but expected to get up to 4".

I do not have the tank, because I am still looking at deals. I haven’t decided whether to buy parts separately, or buy a kit. It depends on whether I can use the filters I already have. I also don’t have a stand I like. I could go 29, 30, or possibly 45.

Do you have opinions on which size is better? Also, I have no qualms about a used hood and light, or stand, but I want a new tank.

8

The filter has three parts, all which collect bacteria. My two filter units are the same, so I was going to divide up parts, so each filter would have some the bacteria.

Will two small filters pull up enough water from the bottom to keep good circulation? I have a bubbler stone I could add. I usually don’t use it, because it stirs up the food, and the fish can’t eat it off the surface very well, but I put it in for about an hour after each water change. I could do something like turn it off for an hour after I feed them, and put it on a timer, so they can settle better at night. the guppies like to settle on the bottom at night, and the danios settle on the top. The loach always hides in one of the decorations.

In addition to the fish, I have a huge, thriving Anubias, and a couple of smaller, bottom growing plants that grow slower, but look really healthy, plus a small Anubias that grew off a shoot.

9

You plan sounds fine to me. It sounds like you are already doing it but the biggest thing is to make sure and use all of the substrate and the existing filter in your new tank. While I would suggest getting rid of some of the deitrius with a gravel vacuum, do not otherwise clean the substrate, their is a lot of beneficial bacteria in it. Don’t clean anything, don’t let anything dry out, keep everything wet and transfer it as fast as possible. If you decide to use a single filter, run both filters for a good month before removing the old filter. As long as you are reusing as much as possible there should be zero problems with putting the fish in the new tank the same day. Your fish will be fine in a 10 gallon tank (or even a 5 gallon bucket) with no filter or heater for a couple hours.

The water itself holds almost zero of the beneficial bacteria (which instead grows on surfaces) and is not particularly important to transfer. It may make it a bit less likely to shock the fish if you keep as much of the old water as possible, but if the water is from the same source ie your tap, all that should matter is that temps are close to each other.

Worst case scenario doing this is you might experience a mini cycle. Keep an eye on your parameters for the first week or so and if you notice things getting bad just do some daily water changes until it stabilizes. With reusing substrate and filters, you will keep most of your bacteria population and it will repopulate itself very quickly.

Someone above suggested setting the tank up and letting it run for a week. Note if you do this you will absolutely have to provide a source of ammonia in the tank during this time or you will end up having the opposite of what you are looking for and end up starving and killing all of your current bacteria population. Personally I think this is unnecessary step.

As a planted tank enthusiast, my suggesting is a 40 gallon long. It has fantastic aspect ratio to it that allows you to create true depth. By far my favorite tank size to aqua-scape.

10

First, I wouldn’t bother moving to a larger tank if it’s only 10 gallons bigger. Second, the easiest way to move the fish would be to take the water out of the 20 gallon and put it in to the 10g tank. Move the fish to the 10 gallon. Move the substrate and the filters with the old media to the new tank which can be filled with a mix of old and new water. Run the filter on the new tank for an hour of so without the fish. Then move the fish over.

11

I would love that, and it would be easy to run two 10-20 filters without worrying that they wouldn’t pull up water from the bottom, and be easier to clean, but I don’t know if it will fit in the space.

Do you have one? how long is it? I’m having trouble finding exact measurements online.

12

ALWAYS have two heaters, always, that should just be law. I have two, each one is rated for about 60 or 70% of what it should be to run the tank on it’s own. If one dies (they have lights I can see from where I’m sitting right now), the other one will be able to keep the tank warm enough until I can come up with a new one. OTOH, if one sticks on, I can pull it from the tank, hopefully, before it cooks the fish since it’s not over rated.

As for filters, you really can’t go overboard on the filters. Again, I have two. I have a 40G tank (and replace about 50% of the water each week). Both of my filters, one HOB and one canister, are meant for tanks that are 75 gallons. Either can die and the other one can run the tank all on it’s own. Also, since they’re physically so large I can fit a lot of bio media in them. On top of that, with two of them AND them being so large they require almost zero maintenance. I open up my canister maybe once every 6 weeks just to make sure it looks okay and it’s always fine. Same for the HOB, I pull the sponge out of the bottom and rinse it every few weeks but it really doesn’t need it.

One last thing, as long as you’re making the move, if you’re looking to add, look for a BN Pleco, those things will keep the tank spotless. You won’t be able to find any algae even if you try. I had one from the beginning and felt bad for it since my tank never had any algae. Then it died and I realized that it was so clean because of the pleco. My tank was filthy within about 2 weeks. Fast forward to about 4 months later, the glass is gross, the rocks and plants are covered (and I do have a loach) and I finally get a new, mostly grown Pleco. The tank was spotless in like 2 days. Pretty amazing for a fish that only comes out at night.

13

I have 40 gallon long in my previous post but I was actually thinking of a 40 gallon breeder, the dimensions of which are:

36" long x 18" width x 16" height

What makes it a nice tank if you have plants is that it is wider, which allows you to create nice layered effects (put short plants in front, taller plants in back) and not very tall for its size, meaning you can get away with less powerful (and less expensive) lighting. It does take up a pretty large footprint though.

14

So far, no algae. I take care of the tank at my son’s school, and it started to get a lot of algae, so it has a BN pleco, and yes, he is amazing. Now that there is no more algae, he gets a supplement chip a day, so he won’t starve. He loves him some supplement chips. I swear, he can be on one side of the tank, and I’ll drop a chip in one the other, and he’ll find in in under a minute.

The main thing I want is another yoyo loach, because I don’t think I should have just one.

15

Plecostomus can grow to be 24".

16

OK, so your bioload/water ratio is way above what I would put in a 30 gal already, and you need at least two more yoyos. Alternatively, you could return the one yoyo to the fish store, and then you should be fine with a 30. I always recommend going as large as possible with any change. Then RESIST the urge to fill it up. LOL!

My 100gal is 48x24x24. (It doesn’t fill all the way to the top because of the way the hood fits.) I got it used, stand, hood and all for $75 a few years ago.

There are always folks getting out of the hobby and selling off their equipment. Check ebay, Craig’s list, and even freecycle. The challenge is to not end up with a tank on every wall in the house. LOL!

As for the filters, I would get one rated for the size of the tank, but also run your current filter alongside it. As far as the depth, it’s just a matter of extending the length of the input tube. A length of tubing and a bit of aquarium silicone (be sure what you buy is aquarium safe!) will do the trick. It’s always best to have redundant systems.

Hope that helps!

17

The “BN” or bristle nose, don’t get that big. They still can get to be pretty big, like 8", but the one in the tank at my son’s school is really small right now, and I made sure the store would take it back if I couldn’t find a tank for it when it got too big for the school tank. The algae problem was severe, and we needed something. We had some snails, and they weren’t doing the job.

I know the bioload is high in my tank, but I do extra water changes, and the test strips are always good. I haven’t lost a fish since set-up, except one, and I think there was something wrong with it, because I lost it a few days after I bought it (the store gave me credit, but he was a really cute li’l guy, and I was still sad). The actual fish I have are small now, so that’s why the tank is doing well, I think-- BUT I know they will grow, and this is why I need to upsize.

I’m not worried about a tank on every wall. One is quite enough for me, not to mention I take care of the one at my son’s school.

18

Commons do, bristle noses tend to stay considerbly smaller, like 4-6 inches.

If you’re in a pet store and see HUGE plecos, the ones in 100 gallon tanks that look like giant eels, those are usually common plecos.

19

There are some good deals on used tanks on Craigslist, but I’m worried about buying a used one. How do I make sure it is clean, and then make sure it is free of whatever chemicals I used to clean it? Also, I think I’d want to have it standing for a while just with some tap water in it to make sure it doesn’t leak. How long should I leave it standing before I can be pretty certain there are no leaks? Is 24 hours long enough?

I was thinking to clean it, I’d use an algae and a very mild bleach solution, to make sure I killed of anything alive that might hurt the fish, and then flush it. If it isn’t clear, I could spray lime away on it, rub it down, and then flush it. After I leave it to stand with the water to check for leaks, that would probably flush away any traces of chemicals. Before I started the transfer, I’d dry it thoroughly with a towel, and let it stand to dry some more.

20

DO NOT USE BLEACH TO CLEAN AQUARIA. Or anything else that you might find under your sink. Seriously do not ever, ever do this. This is the voice of sad experience talking.

Scrub old aquaria with a paste of ordinary kitchen salt and water. Nothing else. If there are calcium deposits, scrape them off with a single edge razor blade.

Rinse thoroughly (but a trace of salt won’t hurt your fish). Fill with water to check for leaks. Empty. You don’t need to wipe it dry.

Also the other posters have a lot of good advice (for example I forgot that I always used to put some not very special fish in a new tank for a week or so to get it cycling)