What's better, one large tank (180g) or two medium tanks (90g) ?

[kien]

So I know that I either want to upgrade my current 90 gallon mixed reef to a 180 gallon and close down the 90 gallon, or set up a new 90 gallon sps coral only tank. There are lots of pros and cons for going either way and I think I have thought out most of them, but I figured maybe some open discussion and other opinions would be good.

My personal reasonings have broken it down to two main points.. I like the idea of having two tanks in case one fails. Kind of like a backup. The old don't keep all your eggs in one basket cliche. Over the past week I have ready through tonnes of build threads and have seen some horror stories.. I suppose it is possible that both tanks will fail but hopefully not at the same time! I don't like two tanks because then I have to maintain them both and there is a lot of duplication, potentially costlier, more maintenance ? Anyway, I am conflicted. Thoughts?

[naesco]

Originally Posted by kien

So I know that I either want to upgrade my current 90 gallon mixed reef to a 180 gallon and close down the 90 gallon, or set up a new 90 gallon sps coral only tank. There are lots of pros and cons for going either way and I think I have thought out most of them, but I figured maybe some open discussion and other opinions would be good.

My personal reasonings have broken it down to two main points.. I like the idea of having two tanks in case one fails. Kind of like a backup. The old don't keep all your eggs in one basket cliche. Over the past week I have ready through tonnes of build threads and have seen some horror stories.. I suppose it is possible that both tanks will fail but hopefully not at the same time! I don't like two tanks because then I have to maintain them both and there is a lot of duplication, potentially costlier, more maintenance ? Anyway, I am conflicted. Thoughts?

A quality properly installed tank will last a lifetime.
IMO,Always choose the largest tank that you can afford (and fit in your residence).
For example, the 180 provides room for some of the most beautiful angelfish and most of the tangs.
However, if a reefer decides that he would like to start up a species tank because he has a high interest in a certain species, that is a different decision.

[banditpowdercoat]

1 larger tank better, IMPO Can fit larger fish, and less work. Cleaning, scraping coraline. Spent 3 hrs last night just scraping and cleaning my 45g. I left the coraline WAY to long

[Leah]

If I had it to do all over again I'd do one large tank having said that though I have one tank set up with angels, and I have my reef tank as well. But it is alot to maintain 3ish seperate tanks. I never stop with the upkeep. So I think you need to decide what you want to put into it first and then decide what way to go.

[michika]

How about this idea then, combine the best of both worlds.

Do one big tank, and you can set up a feature around a divider to create two separate sides of your tank which are inaccessible to fish etc. So you'd essentially have the two different tanks you want, but only have the maintenance to do one one single system.

This is a lot cooler on paper, and very non-cool when you read it though.

[christyf5]

I'd do one large, gives you the opportunity to have bigger and a wider variety of fish.

That "eggs in one basket thing" doesn't really apply. If one tank crashes, it still sucks just as hard

LOL I don't know how many of my non-fish friends are asking if I'm keeping my 90 when I set up my 180. I just give them this horrified look. I can't imagine how people do more than one big tank. It gives me a headache just thinking about it

[whatcaneyedo]

Between my 3 tanks and 2 sumps I've got over 300gal of saltwater... I'd much rather have a 225gal with a 75gal sump. The only advantage to having many small tanks is so that you can keep things that arent compatible. I was able to save 4 acans, an open brain, a donut coral, a christmas tree worm rock, and a photosynthetic sea whip all from being eaten by my copperbanded butterfly by moving them to one of my other tanks. Also its easier to move smaller tanks down stairs and through narrow hallways...

[Delphinus]

I agree with the compatibility points, that's why I've always run multiple tanks myself. At one point it was advantageous for me to have at least one system that was completely separated from the others, because of the potential for fish kill (I had a 24" diameter ritteri anemone which could kill off an entire tank full of fish if something annoyed it .. it would just release something that would cause the fish to die within minutes. Happened to me a few times and it was a terrible traumatic experience so I mitigated the risks by putting it in a tank by itself, a dedicated species setup.) I don't have the anemone anymore, sold it, but the legacy of the multiple tanks lives on.

Which brings me to the second point, 2 systems is twice the maintenance work, and so on. In the wintertime, when we're housebound anyhow, it might be less of a concern but in the summertime with vacations and outside experiences taking precendence it's easy to fall off the wagon and it's amazing how quick tanks can go from "A+" to "C-". In reefkeeping, if everything is OK, things can be amazingly low maintenance. But as soon as one thing gets off balance, it can be fairly easy for the house of cards to collapse.

But if you run two tanks off one sump, at least you can leverage the equipment factor. Instead of two so-so skimmers you can afford one really nice one, and so on. but then you're still stuck with the "all eggs in one basket" scenario.

But bigger systems buffer against problems better than smaller systems, so it might lessen the need for redundancy some.

[kien]

Thanks for all the input! I don't think I have a specific need for a species tank. The more I think about it, the less keen I feel about having to maintain multiple tanks. It is enough to maintain the display and the sump! One big tank it is then. You made a very good point at lunch today Tony.. you can easily spread yourself too thin by having to maintain multiple tanks.

[Delphinus]

You could always put your sump in the basement and run the 90g as a way wicked refugium.