Cycling tanks

[ger87410]

Can you add the sand, cycle the tank, then slowly convert it into saltwater? That should work without killing any of the beneficial bacteria, right?

 

[Navarre]

No afraid not.
The bacteria that lives in freshwater is not the same bacteria that lives in saltwater. if you cycle the tank using freshwater and then add the salt, ozmosis will kill all bacteria and you will need to start again.

 

[ger87410]

Thanx for the reply. What I'm talking about is slowing adding the salt. Like, raising the sg .001 a week or so. Shouldn't that allow the saltwater bacteria to grow slowly while the freshwater bacteria dies slowly? How is the bacteria different? Different sp.? What is the limit of salt the freshwater bacteria can stand? Do they just get a little salt then die? What about the brackish water bacteria, is that a different sp.? I already got the tank at a sg of .990.

 

[Navarre]

Basically its the ozmosis that will do most damage. Salt water will try to remove fluids from the body of the creature constantly, freshwater is usually absorbed into the body of creatures so its the complete opposite. Changing from a freshwater to a salt water environment would cause these creatures to litterally erupt and explode

By slowly raisng the salinity,this will slowly kill off the bacteria and replace with more salt bacteria but i dont understand the reason for doing this. By going down this route means that the tank will take just as long to cycle as starting with a tank full of salt water.

If you are going to raise the tank by .001 sg per week and your tank is already at .990 then you need to add .033 more sg. It will take you another 33 weeks to get the water at the right SG! DUring this time will the water be changed as it might be getting stagnant? (Sorry but i dont know what type of filtration you are using). So this will take you more than 6 months to reach the right sg and then you can consider it ready for stocking. If you simply added the right amount of salt on day 1 then depending on the type of filtration you use you would be up and running within a few days up to 3 weeks

 

[ger87410]

Thanx for the reply. I don't think I'll go down that route anyways. I was going to convert my brackish to saltwater, but I gotta replace the gravel w/ sand. I don't remember the type of filter I have but it's designed to handle a much bigger tank. What kind you recommend? Do you know at what salinity the saltwater bacteria can start to live in? How about the salinity level fw bacteria dies in? Thanx again guys.

 

[Navarre]

Hmm.. a difficult question really. I would think that if you were to increase the salinity over the course of a week or so then you will be ok. INverts for example like slow aclimatisation (a few hours to adjust the salinity). I think that if you gradually increase like this then you might well get away with this.

The type of filtration thats on offer today are varied and many. Ask 100 marine hobbiests what they think is the best filter and you will likely get 100 different answers

Personally i prefer t ouse a natural form of filtration. The berlin method is a tried and tested type of filtration that works extremely well ( Basically Live rock and skimmer)
I use an eco mud system. A run a sump with a mineral mud in which i grow caulerpa (i hope to be getting Mangroves soon too) to remove nutrients (mainly nitrates). Liverock is in the main tank to provide the main filtration. I have no skimmer on this type of filtration as the extra nutrient usually taken out with a skimmer is used to feed the caulerpa.

Trickle filters are an excellant form of filtration, though it does tend to build up nirates. (you can still get rid of these with a reactor or caulerpa or live rock etc.)

I also have a fluidised sand bed filter in one of my marine tanks. superb at reducing levels but they creat alot of nitrates so i also run liverock and macro algea to help reduce the nitrate.

Hope this helps.

 

[ger87410]

Thanks for the great reply! What does some of you other guys have for a setup? I'm fascinated by this.