Will Changing My Gravel Affect My Good Bacteria

[gowing238]

Hi all,

I have a 30 gallon well established tropical tank which i have recently began planting. I have quite a coarse gravel with no substrate underneath and the plants are not doing to well. So i have decided that my next plan of attack will be to replace this gravel with a substrate covered by sand. The problem is i have a lot of fish in my tank!!!

If i do replace this (very carefully) with the fish still living in the tank, is there any chance that the tank will have to be cycled over again? I have a fluval internal filter and i thought this i where the good stuff lives but need an expert to confirm this for me!

Last thing. What substrate and sand would be good for a range of different plants. Not gotta clue of plant banes sorry!

Cheers for the help

 

[doresy]

Hi, changing the substrate will not effect your bacteria level as VERY little lives there. This is because the bacteria requires a continous supply of oxygenated water bringing food (ie, ammonia) running through its home (ie media). As this only happens in the filter this (as you said) is where it will be found!

As for the question about substrate for good planting, you may be better posting that separately in the plant section

 

[Dorkhedeos]

It shouldnt effect it that much as long as you arent using a ugf. It will effect the bacteria that remove nitrate though

 

[cryslea]

It shouldnt effect it that much as long as you arent using a ugf. It will effect the bacteria that remove nitrate though

There are bacteria that remove nitrate? I thought the only way to remove nitrates was through water changes.

 

[Dorkhedeos]

Well, you just learned something new then, the bacteria live in anaerobic conditions. this doesnt mean you can skip water changes though. You still need to do water changes because they just help reduce it.

 

[Bignose]

Most of the beneficial bacteria is going to be in your filter. There is going to be some pretty much everywhere in a mature tank. But, when you remove some, the remaining bacteria will start to grow and will quickly make up for the lost ones. I doubt that you'd even be able to register a spike if all you chance in the gravel.

Be just a little careful there, Dorkhedos, since not all gravel contains the anaerobic bacteria. The gravel layer would have to be pretty thick, so that the water down there was almost compltely stagnant and devoid of oxygen. In a typical aquarium, this isn't going to happen. You're going to need several inches of gravel before you even have a chance of it to grow. Something like soil is also good for developing anaerobic zones, too, and you don't need quite as much because the soil packs together tighter letting less water in.

 

[Dorkhedeos]

Whoops I forgot its harder to do with gravel than with sand or dirt