# Question about tying in an additional tank



## Reef Druid (Jun 27, 2014)

Hey everyone just looking for some advice.

I have a 40B that I plan on tying-in to my current 90 gal DT system. The 40B will be a frag/growout tank. When everything is plumbed and ready-to-go, what is the best method for bringing the 40B online? I plan on having it completely empty to start out. Bare bottom, with perhaps some EC frag trays, and the lighting. Is there anything special I need to do when bringing that much "new" water" into the system (besides making sure my params match), or can I just open the return valve at small increments over the course of X time? I am essentially diluting the system, correct?

Thanks everyone,


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## fesso clown (Nov 15, 2011)

Just make sure that the salinity and temp of the NSW matches and you are good to go.


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## altcharacter (Jan 10, 2011)

Yep, treat it like a water change. Instead of changing the water you're just adding new fresh water to the system.

Good luck!


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## Reef Druid (Jun 27, 2014)

Awesome, thank you both for the confirmation.


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## mules (Oct 29, 2013)

You are making a 50% ish water change. Depending on what coral you have you should also match alk, ph etc.. To not shock anything


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## altcharacter (Jan 10, 2011)

It's a 40B so more than likely it's not filled to the top and more like 33g or so depending on where the bulkhead is.

Also, I'm pretty sure he has a existing sump so It's not really 50% but more like 33% or even less. I wouldn't worry too much about matching up numbers exactly since the flow isn't going to be crazy going thru the system. I would worry if he was running 1200GPH return pump!


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## fireangel (Aug 3, 2013)

I did basically the same thing adding 2 60gallon frag tanks to my 90 gallon display and sump. All i did was match salinity and temperature in them and then turned on the pump to the new tanks. i did it one tank at a time but still the same idea. I had no issues at all. good luck.


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## cerebrous (Jan 30, 2013)

How are you guys pumping the connected systems? 

Are you using a single sump and two return pumps?


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## fireangel (Aug 3, 2013)

I am using 2 separate pumps for my set up.


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## Reef Druid (Jun 27, 2014)

I am using one 1200gph to service both tanks.


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## Crayon (Apr 13, 2014)

I have 2 separate supply pumps as well. It means I can adjust flow rate in both tanks individually.


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