Substrate change...an idea

[Taelen]

So in the past I have posted inquiries with regards to the best way to switch out substrates in an established tank. In my 38g, non-planted I have some blue gravel that I'd like to swap out for some nice sand to match my 44g planted.

I have been thinking about doing this for a while but wasn't looking forward to the day long chore. My thought is this and I'd like some feedback on this idea. Would it not be possible to simply divide the tanks into quarters, 1/4 of the gravel out, lay down the sand to take up the space the gravel was in and let it sit for a week or two so that the bacteria make their way over into the sand. Then take on the next 1/4 of the tank etc...I was going to leave the gravel I moved in the tank there until I was ready to move the next 1/4, then remove that first bunch of gravel.

Any thoughts or things I'm missing?

 

[Purrbox]

Your basic idea is sound. As long as you are leaving you're filter undisturbed, there really isn't any need to swap out the substrate in stages. Just keep an eye on your water parameters for a mini cycle, but in most cases you probably won't see one. Changing it out in stages will probably lead to some mixing of the substrates and will make it harder to get completely rid of the old substrate. Since it sounds like you're trying to break up the task in terms of time though, it should work just fine.

 

[neilanh]

Agreed, as long as you don't disturb your filter I don't see any need to go in stages as far as the bacteria are concerned. Yes, you'll lose what's on the gravel, but what you have in the filter should be able to hold it's own pretty well. Like Purr mentioned, watch your parameters for a bit, but I think you'd be fine doing the swap all at one time.

If you're wanting to break it up in stages due to time, your plan will work as well.

 

[Zagz]

For tanks under 50 gals there should be no need to worry if as mentioned the filter is established. If concerned you can put some of the old substrate into a clean netting and sit on the new substrate.

For larger tanks I would do the substrate in halves as opposed to doing it all at once. For example in my 75 gal I have 100 lbs of sand. I am quite sure if I had changed out all the gravel to sand at once, I would have had some cycle issues. Of course the fish you keep will help dictate that as well. My 75 gal is discus and they do not tolerate parameter changes.

 

[Taelen]

Thanks folks, those were the answers I was looking for. =)

I'm a bit nervous though doing all the substrate at once, I knew a lot of the bacteria was in the filter but I figured there'd be a significant amount in the gravel as well.

Zagz, since I used this substrate to originally seed my 44g planted, I missed the obvious, that I could just place the gravel in netting or pantyhose and let it sit on the sand that way, it will look goofy for a bit but I think that's what I'll do.

I'll keep you guys posted.

 

[Zagz]

It only looks goofy for a couple of weeks. And worth it IMO if you are at all concerned.

 

[Taelen]

Yep, agreed 100% =)