combined freshwater/saltwater tank

[csababubbles]

I've been working on converting an empty aquarium into both a saltwater and freshwater habitat for a few weeks not and its almost done. The tank is a reef-ready 90 gallon aquarium. I got some glass pieces cut by my local glass shop and installed it inside the tank so that it divides the space inside into two compartments. There is an overflow on each side of the tank. The right overflow drains and returns saltwater to the saltwater portion and the left overflow returns and drains freshwater to the freshwater side. Underneath I have two sumps. One sump has a tunze 9010 skimmer, ato, heater, carbon reactor, and return pump. The other sump (for freshwater) has a marineland powerfilter, heater, return pump and a carbon reactor.

The tank is finished and I am just leak testing at this time and if its good I should have live rock and water in the system by end of the week. Once its all setup and going this weekend I will post pics of the entire set-up in case any of you guys are curious. I should have livestock in it (on the freshwater side) in another two weeks (if all goes well) and the marine side not for about 3 months (except the liverock).

 

[brady816]

sounds cool my son was talking about the same thing if i have ever seen something like this..

 

[dnjan]

I'll be curious how much salt creep affects the salinity of the "fresh" side.

 

[csababubbles]

there should be minimal problems as the top of both sides are sealed off with glass tops and the sumps half about 2ft of space between them. the glass divider between the two sides is all the way to the top and has a glass "top" that I siliconed on top of it to reduce chance of transfer between the salt and fresh water. I am filling with water and will monitor the salinity on both sides to see if there is any exchange or other issues I may have missed.

 

[dnjan]

That sounds better. Are the glass tops completely covering each side, or is it more like euro-bracing?

 

[roscoe]

This sounds like a awsome looking tank!! What type of inhabitant are you planning for your fresh water side will it be planted with live plants ?

 

[returnofsid]

Will the saltwater side be a Fish Only or Reef? I ask because I would be concerned about using high intensity lighting over the Fresh Water tank. I'd think it'd cause some major algae issues. This does sound like a really cool idea and I'm sure we'd all love some pics!! One other thing...if it's a reef system, having a glass top on it could also cause some problems with lighting and heat issues, as well as pH issues.

 

[csababubbles]

That sounds better. Are the glass tops completely covering each side, or is it more like euro-bracing?

glass tops completely cover the top. all water/gas exchange will be accomplished via sump

 

[csababubbles]

Will the saltwater side be a Fish Only or Reef? I ask because I would be concerned about using high intensity lighting over the Fresh Water tank. I'd think it'd cause some major algae issues. This does sound like a really cool idea and I'm sure we'd all love some pics!! One other thing...if it's a reef system, having a glass top on it could also cause some problems with lighting and heat issues, as well as pH issues.

Lighting consists of actively cooled T5 lighting. Its a single fixture but if problems do arise, I can always buy two short fixtures so that each can be lamped for each side appropriately. Freshwater will definately be live plants as I have another freshwater tank that I can simply transfer over my excess growth. I've been meaning to thin it out anyways and this is perfect excuse. Marine side will be a full-blown reef.

The glass top may cause issues but I think I have most issues minimized. Ambient air in room is always about 65F. The sump is open-topped that I can add a fan to blow over it if needed. A low pH may very easily be solved by adding solid kalk to my top-off container, as this will raise the ph. Hopefully this will work but careful observation and testing will prove if I am right or wrong.

As for livestock, I have yet to decide which combination will yield the most pleasing contrast to the other side.

Do you guys think I left anything blatantly obvious out? How about stocking suggestions for the two sides? I got tons of fish and corals I can add from my other tanks or I can always trade with local people.

 

[dnjan]

You should just be able to use a layer or two of windowscreen beneath the lights on the freshwater side if it is too bright.

I would guess that heat on the freshwater side might be a bit of a problem (I assume you will be wanting a temperature lower than standard reef temp there) - perhaps more fans on the freshwater sump?

 

[returnofsid]

Planted Freshwater tanks do great at the same or similar temps as our reef tanks. They also do great under T5 lighting!! I've got T5s on my 75 gallon reef and I think they're awesome. Great choice for lighting that will suite you're dual tank!! As I said, I'm sure looking forward to pics!! Are you going to run Co2 on the FW Planted side?

 

[csababubbles]

I have individual heaters for each side but I doubt I will be able to have a large temp difference between the two sides. I plan on keeping the temp around 80 degrees all around. My marine tanks range from 76-84 and my current freshwater planted tank is 78-80, so temps for both types of tanks are very close to each other regardless.

 

[dnjan]

I would think that the fish interraction at the divider would be interesting ...

 

[csababubbles]

Planted Freshwater tanks do great at the same or similar temps as our reef tanks. They also do great under T5 lighting!! I've got T5s on my 75 gallon reef and I think they're awesome. Great choice for lighting that will suite you're dual tank!! As I said, I'm sure looking forward to pics!! Are you going to run Co2 on the FW Planted side?

Yea I thought the T5 fixture would be very good for both fresh plants and corals.

I'm am going to hold off on any co2 supplementation until I have the whole system running flawlessly for a few months. At that point I will make the decision.

 

[csababubbles]

I would think that the fish interraction at the divider would be interesting ...

That's what I'm talking about...imagine the scared look on a school on tetras coming across a clown trigger! LOL

The divider piece is pretty thin so its difficult to see without looking close. A quick glance and you don't even notice it.

The trick is how I am going to blend the two environments into a complementary piece. For substrate I use fluorite but I dont know how akward this will look with marine sand next to it. I have this particular freshwater plant in mind that will quickly cover most of the substrate so it essentially looks like a bed of grass. That may look neat. I've been racking my brain about this project for quite a while and its getting more difficult as I think about it more and more.

 

[91YOTA]

you could always let GSP cover the bottom of the marine side

 

[csababubbles]

thats exactly what I was planning to do to compliment the freshwater side