20 gallon reef - first SW tank

[Higman]

Hi all,

I'm a FW veteran, but completely new to SW. I've got a 20 gallon (that's UK gallons, so probably 22-25 US gallons) that I would like to convert from freshwater to salt. I've been doing a lot of research into marine aquaria, and believe this to be about the right size for what SW hobbyists consider to be a "nano reef". Ideally I would like a larger tank to achieve better stocking and water quality, but this not possible due to both space and cost.

My current FW setup is a fairly simple one. I've got a TetraTec EX700 canister, and a decent quality TetraTec heater.

After researching and researching, and finding a lot of conflicting information on the internet, I've come up with what I believe to be a fairly stable setup that I would like to attempt. Before I start though, I'd like to run it past you guys to see what you think.

Here's what I'm thinking:

Remove substrate from tank, and take out filter media. Buy a stack of activated carbon ready for use.
Lay down some decent white sand.
Buy 2lbs of LR per gallon. Allow LR to seed sand.
Place LR fragments, Bio Home, or similar into canister.
Purchase a decent PH or two.
Either purchase or DIY a protein skimmer.
Get some decent lighting, thinking somewhere in the region of 150 watts.
I have a 3 gallon glass tank that I'm thinking I could use as a sump. I really like the idea of being able to top off the tank from a sump rather than having to pour water into and therein disturb the main display tank.

Also I've read that many people with tanks of this size have found that they have been successful without filters or skimmers, and instead simply rely on just a sump. I'd be interested to know more about that because the low tech approach is very appealing to my wallet!

As for the reef element, that will come later as I get to grips with things! I want to aim toward reef, but I want to work on getting things stable first. This will probably be a single fish setup, three fish at most. I'd be happy keeping a clown or damsel. I'm unlikely to keep anything else because there aren't many other small marine fish that I really like. Also I prefer light stocking in marine tanks, I think it just looks better. I find the reef life so fascinating, with all the little hitchikers that come along with it. Plus I'd eventually like to keep some anemones - not too bothered about the clown living in it, I just like anemones! If the clown decides he likes it then so much the better!

Also, I have a question, a simple one, that I haven't been able to find a straight answer to on the internet: How often do you do water changes with a SW tank? I've read that SW water changes are not as bad as FW changes, being something like 10% every two weeks or so.

Anyway I look forward to reading your replies, and thanks for taking the time to read!

Thanks,
Scott.

 

[joy13]

You really need to do a PWC weekly on a tank that size probably somewhere between 20 and 30% water changes a part of life with any tank. You do have to top off your tank usually daily to keep it from getting to salty. On my 8 gallon I top off twice a day on my 2.5 I top off 3 to 4 times a day only a little bit but it is enough to keep the SG steady. If you are planning on an anemone stay away from CF go with MH or T5 lights. I don't know how well anemone do with LEDs.

The best purchase is a refractometer for a nano tank.

Nothing good happens fast in a saltwater tank.

Last but not least WELCOME to one of the best forums online

 

[Jaybird]

You won't need the HOB filter if you have live rock in the tank. You mentioned 2lbs of rock per gallon....well, that's just a ball-park. It really depends more on the porosity of your live rock. Some rock is more dense than others, and some are very porous, which give more surface area for the nitrifying bacteria to thrive. You could probably shoot for more towards 1 to 1.5lbs per gallon.

I'd recommend ditching the HOB filter and look at a HOB skimmer

You will need be more strict with your PWCs with a smaller tank. Some people do weekly changes. I end up topping up my tank with anywhere from 2L to 4L of RO/DI water to compensate for evaporation and do about a 30% PWC once a month. That's on a 90G. You'll need to do them more often and be a lot more careful with a 20-25G.

 

[Higman]

You won't need the HOB filter if you have live rock in the tank. You mentioned 2lbs of rock per gallon....well, that's just a ball-park. It really depends more on the porosity of your live rock. Some rock is more dense than others, and some are very porous, which give more surface area for the nitrifying bacteria to thrive. You could probably shoot for more towards 1 to 1.5lbs per gallon.

I'm aiming to get a mixture of dense and porous if I can, so that I can support pretty much even quantities of aerobic and anaerobic bacteria. If you're American don't forget that the British gallon is a lot bigger than the US gallon, so 1.5lbs per US gallon is probably about the same as 2lbs per UK gallon. Either way, I'll take your advice and look at it more as a rough guide.

I'd recommend ditching the HOB filter and look at a HOB skimmer

My filter is a canister, not a HOB, I dunno if that changes things. I'm thinking of ditching it anyway because from what I've read mechanical filters become more of a pain in the *** than they're worth on an SW tank. Actually a HOB skimmer is exactly what I'd had in mind. I do not want any internal equipment, as it reduces precious water volume.

You will need be more strict with your PWCs with a smaller tank. Some people do weekly changes. I end up topping up my tank with anywhere from 2L to 4L of RO/DI water to compensate for evaporation and do about a 30% PWC once a month. That's on a 90G. You'll need to do them more often and be a lot more careful with a 20-25G.

I find that with my tropical FW tank I lose maybe about an inch per week, unless the room temp really drops, in which case I can lose that much in one night.

I've read about quite a successful (it was a "tank of the week" on one of the other sites) 20g skimmerless filterless reef tank that got a 10% change bi-weekly, as well as the regular top offs. This tank had a pretty heavy pile of live rock and reef, and seemed to have a fairly advanced and well-established biological colony of various mushrooms, anemones and such. However I'm guessing that the reef fauna/flora was responsible for feeding on a lot of the waste and detritus.

In this case, would a protein skimmer potentially starve a heavily populated reef?

It sounds to me like stocking density also has a lot to do with how often water needs to be changed. I imagine that since I am intending to keep only one single fish, there will be a smaller bio-load, and that my water change regime will be rather different to someone who was keeping more in the same size of tank?

Thanks everyone for the welcomes and of course the advice! And sorry about the long posts!

Thanks,
Scott.

 

[Mitchell0605]

I've read about quite a successful (it was a "tank of the week" on one of the other sites) 20g skimmerless filterless reef tank that got a 10% change bi-weekly, as well as the regular top offs. This tank had a pretty heavy pile of live rock and reef, and seemed to have a fairly advanced and well-established biological colony of various mushrooms, anemones and such. However I'm guessing that the reef fauna/flora was responsible for feeding on a lot of the waste and detritus.

In this case, would a protein skimmer potentially starve a heavily populated reef?

This is probably a tank that has achieved a stage where the nitrates being produced are balanced and removed by natural biological filtration in the tank, thus the tank requires no extra assistance with filtering (exactly like the ocean). Having a Protein Skimmer will not at all strave a heavily populated reef. Welcome to AA.

 

[Higman]

This is probably a tank that has achieved a stage where the nitrates being produced are balanced and removed by natural biological filtration in the tank, thus the tank requires no extra assistance with filtering (exactly like the ocean). Having a Protein Skimmer will not at all strave a heavily populated reef. Welcome to AA.

I just pulled up the website. Tank of the Month - July 2002 - Reefkeeping Online Magazine

It says the tank is 16 months old, and that they currently do a 25% change monthly. They cite clams as being the main reason for their success without a filter. It makes for pretty interesting reading.

Thanks for the welcome, this seems like a great place to be.

Next thing I need to do now is figure out how to go about making a sump out of my 3 gallon tank. Is it likely that my canister filter will have any use on my SW setup in future apart from just running carbon media?

 

[thincat]

If you are going through all the trouble of making a sump I'd go with a bigger tank. A 3g UK tank is to small. If you can get a bigger unit it will give you more volume and make your setup more stable.

 

[Higman]

If you are going through all the trouble of making a sump I'd go with a bigger tank. A 3g UK tank is to small. If you can get a bigger unit it will give you more volume and make your setup more stable.

I was only thinking of using the 3g because I have one lying around. What sort of size am I looking at? Is there a particular recommended ratio of sump to tank size?

 

[dannyb]

Well as big as you can fit or have. The bigger the volume of water, The easyier its to have chemicals under control and the slower it has time to change.

 

[Higman]

Well as big as you can fit or have. The bigger the volume of water, The easyier its to have chemicals under control and the slower it has time to change.

Ah I see... so a sump acts to add volume to the tank... believe it or not I never thought about it like that before! I can really see the merit of having one now. Ha, you must think I'm such a novice for not even knowing that already.

Anyway I've been doing some thinking. See the problem I have is that the tank is on top of a chest of drawers, rather than a dedicated tank stand. Because of this, I have no room under the tank to place a sump, so I'm a bit limited in terms of space. I've got maybe roughly a 9 inch by 24 inch space beside the chest of drawers, which is currently where I've got the filter.

I guess what I'm saying here is maybe it would be a better idea to wait until I have some more space - that way I can have a tank stand and figure all the rest of this stuff out when I'm not doing everything on such a shoestring budget in a space the size of a darn postage stamp. I'd rather give my livestock the best chance at life as I can give them, than put that factor at risk simply because I'm so eager to give it a go.

I think I probably got carried away with the idea of going saltwater! I'm not discouraged... just wiser. Like you guys say, nothing good in saltwater happens fast. Mark my words I'll be back on here one day when I get my dream reef tank started. Thanks so much for all the advice, I've learned a whole lot in a short space of time.

I'll keep lurking. Speak to you all soon!

Thanks,
Scott.

 

[dannyb]

You dont have to have a sump. It can help things out. You can still have a reef going in a 20g.

Maybe start that up, See how you go with that for a while. Then when you have the money, Go something big like 125g or more.

Then you'll have the experiance and be able to have in there whatever you choose. If it fits the room requirement.

Hope i've helped. Enjoy.

 

[Higman]

You dont have to have a sump. It can help things out. You can still have a reef going in a 20g.

Maybe start that up, See how you go with that for a while. Then when you have the money, Go something big like 125g or more.

Then you'll have the experiance and be able to have in there whatever you choose. If it fits the room requirement.

Hope i've helped. Enjoy.

There are two things that bother me about doing this reef thing where I am now. One is cost. The second is space. Storing 5 gallons of saltwater overnight in a room that is only 7'6" wide, once a week, is going to be impractical. Bare it in mind that I live in this room, along with my fiance, and we spend most of our time in there. Having a big bucket of water kicking around is going to be irritating at best. Or maybe not? 5 gallons isn't too bad... hmm I'll have to think about that one some more.

I'm looking at the cost of lighting at the moment and it seems that my best bet would be the aquamedic ocean light, which is 24" long and in the region of £150. That's fine for me, I think that's pretty reasonable. The only problem is that the costs don't end there. Live rock is also really expensive, so are corals! I worked out that the LR alone could cost anywhere between £150 to £200. Individual corals can cost in the region of £20.

I just wanna be able to do this thing properly. If I work out the whole project to be about £450-£500 in budget for the 20 gallon tank, I can save for it and get exactly what I want.

 

[Mitchell0605]

If you want to do that then you should visit you LFS and plan out your tank according to the prices of the fish and corals you want. Then try super hard to not deviate from that plan. (And trust me, you'll be tempted beyond belief).

 

[Higman]

If you want to do that then you should visit you LFS and plan out your tank according to the prices of the fish and corals you want. Then try super hard to not deviate from that plan. (And trust me, you'll be tempted beyond belief).

I have no specific plan for corals. I know exactly what fish I want; one single clown, either a black ocellaris clown, or a true percula. Maybe a few inverts, clams, crabs, etc. I would like to eventually keep an anemone.

That's it. Nothing exciting, nothing ambitious, just a fairly basic reef. Think I can do it with just L/R, powerheads and nothing else? Something tells me that it's not possible.

Yeah, 150 gallon tanks are nice, but, who can really afford to pay out the £1000's for the tank, the lights, etc. these days? Seriously if I ever find myself having enough money to set up a tank like that I'll do myself a favour and buy something more productive, like a car.

I'm not greedy, I don't want to have loads of fish and huge banks of coral. I just want to have my own little reef, my one clownfish, and preferably an anemone. That's all folks.

 

[Mitchell0605]

That's it. Nothing exciting, nothing ambitious, just a fairly basic reef. Think I can do it with just L/R, powerheads and nothing else? Something tells me that it's not possible.

You could especially if you get 3, 4, 5 clams in there to really filter that water. But you have to make sure you have really good lighting for the clams and the anenome.
BTW Anenome + Clown Tip #1 - If you want to make sure the clown uses the anenome buy a bonded pair clown+anenome. If you buy them seperate there are no guarantees it will use the anenome. Mine sleeps in some hair algae about 10cm away from a perfectly good anenome.

 

[Higman]

You could especially if you get 3, 4, 5 clams in there to really filter that water. But you have to make sure you have really good lighting for the clams and the anenome.
BTW Anenome + Clown Tip #1 - If you want to make sure the clown uses the anenome buy a bonded pair clown+anenome. If you buy them seperate there are no guarantees it will use the anenome. Mine sleeps in some hair algae about 10cm away from a perfectly good anenome.

Would 150 watts MH be sufficient for that many clams, coral, and an anemone?

And in response to your tip, like I said earlier, I'm not too bothered about the clown using the anemone, and I'll tell you why. If I ever find a bonded pair for sale then I'll consider it, but to be honest I seriously don't think that this is a good way to shop for anemone. I've done a whole lot of reading about them and gathering from what I've read, while this approach may work for an expert, I really doubt it's going to go well for a beginner such as myself.

Anemones have a pretty low survival rate in the home aquarium as it is - even big public aquariums have a hard time keeping them alive. As far as I know most anemones expell their zooxanthellae the moment their collected, with survivors being the exception, not the rule. To my eyes, success is all about picking the right specimen in the shop. For one thing, you really need to look at the anemone and ask questions; is it healthy? Has it expelled it's zooxanthellae? Is the foot fully anchored? How long has it been in the shop? If you're looking for a bonded pair you're going to have much less chance to "shop around" for a good specimen, because the chances are there's going to be lots of good individual clowns and individual anemones, but very few bonded pairs. An impulse buy here is likely to end in failure. Not being an anemone expert I usually have no idea what anemone I'm looking at - just like everyone else I have to do my research. I might find that I've ended up with a very healthy, but very hard to keep specimen.

In short I think it's much more important to have a tank with a healthy clown and a healthy anemone, even if the two won't have anything to do with eachother. I would very much prefer to buy a clownfish first, get used to keeping it and let the tank adjust to the bioload of the fish, before I added an anemone. I'd hate to take a bonded pair and then break that bond by making amateur mistakes that end up killing off the anemone.

 

[dannyb]

I've had a few different types of anemones. At the moment, I have a Green Haddoni Carpet anemone, And a BTA. The BTA moves all the time, Its never happy, but he's doing fine. He'll stay in one spot for a while, Then move again. Im not sure why.. The carpet on the other hand has fully anchored himself down on the substrate. Then i went and brought 2 Black and White ocellaris, Juvenile, One small, One bigish. At the start they didnt host anything and they were fighting a little bit, Then the bigish one started hosting the carpet and the little one followed after a while. Now they're paired up and hosting the carpet.
But yeah, Tbh.. I dont think anemones are to hard to look after. I feed my Carpet once a week to once every 2 weeks and same with the BTA. And they seem to be thriving.

Anyway, Whatever you get. Good luck.

Also, 150w MH will be enough lighting.

 

[Higman]

I've had a few different types of anemones. At the moment, I have a Green Haddoni Carpet anemone, And a BTA. The BTA moves all the time, Its never happy, but he's doing fine. He'll stay in one spot for a while, Then move again. Im not sure why.. The carpet on the other hand has fully anchored himself down on the substrate. Then i went and brought 2 Black and White ocellaris, Juvenile, One small, One bigish. At the start they didnt host anything and they were fighting a little bit, Then the bigish one started hosting the carpet and the little one followed after a while. Now they're paired up and hosting the carpet.
But yeah, Tbh.. I dont think anemones are to hard to look after. I feed my Carpet once a week to once every 2 weeks and same with the BTA. And they seem to be thriving.

Anyway, Whatever you get. Good luck.

Also, 150w MH will be enough lighting.

Sounds to me like your BTA doesn't like the flow in your tank. A close friend of mine found that he had the exact same problem as you, a wondering anemone, and solved it by changing the LR arrangement and powerhead positioning. This was apparently completely unintentional, the rearrangement was due to boredom. If I remember correctly the anemone settled in a sheltered area with the tentacles just poking out into the faster flowing open water.

Re the lighting, I figured as much, being around 7.5 watts per gallon. Even with the US gallon it's still something like 6.8 wpg. Put a light like that over a FW planted tank and you'd probably wake up the next day to find the whole house is now a jungle!