Changing Substrate in Cycled Aquarium

andrewsz123

Does anybody have any advise on changing the substrate in a cycled planted freswhater aquarium. I am looking to change the substrate for the benefit of my plants, they are way too big and i am noticing the roots are not taking hold well. I also have fish and the tank is about 3 months old. Any advise would be greatly appreciated.

redchigh

I would get an extremely fine gravel and just pour it into the tank (after washing it), leaving your old rocks in place. The new gravel should fill in the gaps. :)

SinCrisis

Smaller gravel will eventually mix to the bottom when gravel vacing is done wouldnt it? smaller rocks will end up at the bottom when its disturbed.

redchigh

Ah, Gravel vac... Forgot some people still do that. ;)

If the gravel is too large for plants, then the smaller gravel/course sand will probably just fill in the gaps.

After a month or two you can try to get the original gravel out, leaving just the new gravel...

Of course there's probably no problem with just taking the gravel out... The filter should be well-colonised with bacteria, and if you add several plants you shouldn't have a problem. (I would use at least a few fast growing plants..)

andrewsz123

Thank you for your posts, that seems like the most viable route. Im not into my gravel it at its blue! i was thinking of what my fiance would like when making the purchase, bone head move..lol

redchigh

He's probably like black sand. :)

SinCrisis

black sand = best substrate ever.

Byron

Assuming this is the aquarium in your log photos, yes, you want to remove the blue completely and not mix something with it.

This is not difficult, and can be done one of two ways. You can leave the fish in the tank and just remove the existing gravel and carefully pour in the new; some do it this way, though I don't like to. I prefer having an empty tank to work in so I can arrange things without worrying about fish, plus without water it is easier to arrange the substrate, plant the plants, then fill and have less cloudiness.

A spare tank with water from the existing tank, plus the filter & heater moved over to the spare, and the fish netted out and into the spare. Then you can take your time to reset the main tank.

Dark substrates are best, both for fish (less stress=better health) and plants (visual, they look nice with a dark substrate and background). This is a 29g so not too large to make a plant substrate like Eco-complete or Flourite possible, but plant small-grain gravel or sand will also work. Just make sure it is dark, whether black, dark brown or gray, or natural.

Once the substrate and plants are in, fill and add water conditioner, then move the filter and heater back and the fish. Don't wash the plants or any decor, or filter; plenty of bacteria will have colonized these, plus the plants assimilate ammonia greedily.

andrewsz123

Byron,

Sounds great thats what I was going to do. In reference to the eco complete I was reading that initially that substrate increases the PH for about 2 weeks until it levels off, is this correct? How long after adding water conditioner does to take for the chlorine to leave, subjust to the water temp can I add the fish back to the tank immediately?

SinCrisis

When i added eco complete to my tank my ph only rose by .2 Unless your ph is already really high, you should be ok with adding it without worrying about ph spikes. It does make your water cloudy for a while though since theres a lot of dust, even if you rinse them a lot.