Upgrading from 12 gallon to 40 gallon...advice.

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Discuss all topics related to freshwater and planted tanks.

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Upgrading from 12 gallon to 40 gallon...advice.

by Decon1

Greetings! I'm new here, so forgive me if a similar post has been made before.

I currently have a 12 gallon tank with a few sharks, a gold gourami, and some live plants and will be upgrading to a 40 gallon tank soon.

All I'll have at this point is the current set up for my 12 gallon and the 40 gallon tank solo.

I need some recommendations on what type of filter to use. Any suggestions?
And I assume I'll need a new heater for the 40 gallon tank as well.

Also, would it be safe to cycle the new tank with my current fish? I'd hate to have anything happen to them since they survived me this long.

Any other tips or fish suggestions would be greatly appreciated!


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by Tmercier834747

Firstly I understand how excited you must be right now, if even during the process of waiting for someone to respond you haven't already started filling your 40 gallon with water and fish..lol Here's some advice:

1. Substrate: choose a substrate ---carefully---. As you already have live plants in your 12 gallon I won't go much into detail. Whatever you choose you're not necessarily stuck with, but should you decide you're not being serious enough in the plant category and you want to do some crazy stuff down the road make sure you're prepared, so you're not removing tons of gallons of water, pounds of substrate, and fish from your aquarium in order to ''upgrade.'' I'm speaking from personal experience as this wasn't even fun with a 16 gallon, nor was it fun for my fish.

2. Cycling: Cycle the new tank only with fish you don't fear losing. Using established filter media from the filter in your 12 gallon will more quickly colonize your new tank with beneficial bacteria, however the bacteria need things to feed off of. For this you should probably get some cheap, hardy fish, possibly even live feeders (a LOT can be purchased at a cheap price, though for speeding up a 40 gallon cycle, I'm not your best source as I've only had to deal with anything as big as a 16gal. Since you probably don't have a lot of filter media in your 12 gallon, you could even supplement more bacteria by taking gravel from it and placing it in a nylon sock, then hanging it next to your filter intake in your 40gal, as gravel is often a holding pen for beneficial bacteria, but not nearly as much as your filter.

3. Filtration: I don't know what you use for filtration now, but I've used marineland filters in both my aquariums and the bio-wheel has not failed me. My water is always crystal clear, which is actually a pretty common attribute among aquariums. lol I won't swear by them but I think one or two Hang-on-the-back's would work fine judging by your fish stock atm. If your 12gallon is an eclipse w/integrated filtration on the hood, don't be discouraged, the non-integrated marinelands are MUCH better. But you could go overkill and get a canister filter. They're much more spendy but you'll probably never have to worry about ''upgrading'' for this tank should you get one, they're also slightly more complicated.

4. Good luck. :)

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by spongebob4460

You could easily do a fishless cycle, especially since you have a current tank to keep your fish in, while you cycle the new tank. This will take roughly two weeks if you use existing filter media and substrate. You can check the article section of this site to learn how to properly do a fishless cycle, this will prevent any possibility of your fish dying.

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by miami754

Yeah, I agree with Spongebob - check the article section and do a fishless cycle. Then you don't have to worry about killing your fish. Even with the fishless cycle, it is very important to move as much bacteria over to the new tank just like Tmercier said. Water contains very little bacteria so don't worry about moving any of it over. Instead, move the filter media over, a biowheel if you have one on the old tank, a bunch of the substrate, and any decor you have. You can greatly speed up the process if you do this.

For filtration, with a HOB filter (hang on back) you typically want a filter that specs 10x the output as gallons in your tank. So for instance, since you are moving to a 40 gallon, you would want a filter that specs around 400 gph (gallons per hour). It doesn't have to be quite this much, but make it close. Even though the filter says 400 gph, his spec is determined with no filter media in the filter and with zero lift. In actuality you will be lucky to get a 3-4x multiplier in your actual tank. For specific brands, I always use Emperor and have never had a problem. They are quiet, work nicely, don't break, and I like using bio-wheels. I know others who use Penguins and they also like them. I guess these would be my recommendations for a HOB filter. If you want to go the canister route, let us know and we will steer you in the right direction there.

Good luck with your upgrade. By the way, what kind of sharks do you have in there? - just curious.

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by Peterkarig3210

I just started a new tank and used the filter I was using in my 20 gallon for my new 35 gallon long as well as some plants and the thing cycled right away. It took about 3 days for the muddiness the plant growing substraight (fluorite and Eco-Complete mixed) created to clear, and then I just added the fish. I added about 100 mosquito fish babies and about 35 tilapia babies. The ammonia and nitrites have remained at zero, and I use a Rena-Filstar XP3 canister filter rated to filter a 175 gallon tank. It cost about $120.00 and was the best filter for the money in my opinion, and I can sit the tank all the way back to the wall which you can't with a hang-on filter.
I think if you use the filter from your old tank without cleaning it and add the plants you'll be able to put your fish right in. Just leave the 12 gallon alone till you get the 40 gallon tank so there is a tank full of water, the plants are planted, and the mud has cleared. I would set up a new bigger filter in the big tank and when the water clears remove 12 gallons of water and add the 12 gallons from the old tank and set up the old filter with it at least for a couple weeks if not permanently. The new tank should start cycling immediately because of the old filter full of bacteria and the plants, so I would add the fish when you switch the old filter over. Out of say 135 baby fish I haven't seen any dead ones and it's been about 2-3 weeks, and the cycle has been going from day 1. I just added 12 algae eating shrimp and a 3/4 gallon upside down tank as well!
As long as you use the new filter to get the water clear and add the fish when you switch the old filter over, along with all the water from the 12 gallon tank, you should be fine and the cycle should already be going from the old tank's filter bacteria. Just don't clean the old filter when you put it in the new tank, it'll possibly wipe out the bacteria colonies needed to seed the new tank and it's new bigger filter. Adding the 12 gallon's water is the least important thing, but the pH of the new tank may be very different than the old tank, and this will dilute the difference a bit. I guess you might do a big water change in the old tank a day before putting the fish in the new tank as this will get the fish more used to the pH of the tap water and will be less of a shock when you do move them over.
Last thing: You probably already know, but I hope you always use dechlorinator when you put tap water into a fish tank.
Hope I didn't tread on any toes giving my way to do this!

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by Zambize4899

I use Marineland/Penguin, too, and love it. It's super-easy and plenty of room to put in a second pad, if you're so moved.

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Joined: Wed Mar 26, 2008 2:08 pm

by Decon1

Thanks so much for the great replies! So much to think about! I think I'm going to try out the fishless cycle first and see how that goes. If I see it taking too long then I might just go ahead and throw in some inexpensive fish. But knowing my luck the feeders would out live my other fish!

I just picked up the tank last night, and the woman from whom I bought it mentioned she might have a filter stored away somewhere...so that would solve my problem. Hopefully.

However, I did go to the pet store last night to check out the filters and the hang on the back filters are reasonably priced. I did see the one's mentioned in this thread and I might go with the biowheel...but haven't settled on it just yet. Just he one draw back for me is the dead space behind the tank, and having it stick out 5/6 inches from the wall.

As far as my fish, I have a pair of Bala sharks, one gold gourami, and I forgot to mention a pair (male/female) red velvet sword tails. :) ... oh and a baby snail that stowed away on one of the plants.

My 40gallon is taller than it is long. I'm guessing this would be a better tank for community fish like I have now, and not so good for cichlids? I was at the pet store and was really intrigued by the behavior and look of the Convict Cichlids, and thought of maybe just using the new take for them...


Upgrading from 12 gallon to 40 gallon...advice.

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