The Planted Tank Forum banner

Replacing my substrate

2K views 18 replies 7 participants last post by  lksdrinker 
#1 ·
I have a 55 that's been up and running for about 9 years now. It has the same substrate from day 1. The substrate is organic soil topped with eco complete. I feel like it's time to replace it. My plants have been not getting sufficient nutrients lately as they have been browning. I recently starting adding some fertilizers in the water column and that has helped a lot. This is the first time I have added any kind of fertilizer since I began the tank.

For those of you who have replaced substrates ... what are your thoughts about the steps needed to do this? I do have a few fish ... angel, 2 corys, 5 otos. I do have a 10 gallon I was planning on keeping the fish in while I did the change. I know a 10 is small but it would only be very short term. I plan to do this in one day and I will keep a lot of the existing tank water to put back in with the new substrate.

My plan is to use the same kind of substrate design as I have with organic soil topped by eco complete.
 
#2 ·
Definitely wait for someone with more experience to answer, but from what I've read here on TPT, the nutrients in your soil are used up fairly quickly (a few months or less). I'm not sure if the soil reabsorbs nutrients when organics and such break down as I haven't done a dirted tank, but I'm sure someone else would know.

I do know changing substrate can wreak havoc since so much of your biological filtration lives in and on the substrate. So trying to do this in one day is a bad idea as you will be doing a mini-cycle on your tank. You'll need more time for everything to cycle, though not as long as a new tank since you still have other surfaces.
 
#4 ·
from what I've read here on TPT, the nutrients in your soil are used up fairly quickly (a few months or less).
A few months or less is a bit of an exaggeration. Now the 9 years that the OP has had this substrate in the tank is certainly long enough for the nutrients to have been used up by now for sure.

I think the OP has the right idea though (unless you choose to try some root tabs first as recommended above). Use that 10 gallon as a temporary storage container for the fish (even buckets would work in a pinch). Drain the 55. Scoop out the old substrate and add in the new as if you were setting this up for the very first time. Refill the tank and anticipate a cloudy mess that might require a few more drain and refills. Wait for the cloudiness to settle and add your fish back in.

Dont worry about keeping the old tank water. Really no benefit to doing so. Just treat it like a 100% water change and make sure to use dechlor if needed.

Sure there is a chance you'll lose some of the beneficial bacteria that has colonized on the substrate; but it sounds like your tank is not heavily stocked and whatever bacteria has colonized on your filter should not be affected at all by this process. If you're concerned I suppose you could try to scoop the eco complete off of the dirt and re use that as a cap on your new substrate.
 
#3 ·
@matt11390 Have you tried any root tabs?

Edit: Unless you just want to change for the sake of changing. If it was me and I had no other reason to swap I think I might try root tabs first. Others may have some other suggestions.
 
#13 ·
I could smell death.

As I mentioned in small tanks with canisters yes it would have a larger effect, but there's a ton of surface area on gravel/sand, plant leaves, etc, etc. How would you explain the OP not having a filter for years.

Initially the filter is a place to house media since the the plants aren't growing and you need mechanical, chemical removal. But once the bacteria develops in the the tank the filter on a tank to me is primarily a flow device and takes a back set to the biological filtration within the tank. How do you explain the OP didn't have a filter for 2 years?

Again it's not the dynamic in every tank, but in a big planted tank, I do believe this is true.
 
#14 ·
smell death? You're like those cats in the nursing homes lol!

You're correct. there is a ton of surface area on the gravel, sand etc.; but not as much surface area as any biomedia might offer. the BB will colonize on any surface it can find whether a tank has a filter or not; whether that tank has substrate or not; whether that tank has plants (live, or fake) or not, etc. I'd credit running a tank for years with no filter on the plants' ability to consume the pollutants and act as a natural filter more than their surface area offering space for a large colony of bacteria to thrive (and I'm not denying that bacteria will colonize on those surfaces along with any/every other surface in the tank).

My point/outlook on it is that biomedia offers far more surface area than anything else in a tank (except when that tank has no formal bio media lol). I suppose any surface in a tank could be considered bio media once beneficial bacteria is growing there.

I'd be willing to run a planted tank with no filter; but I wouldnt attempt the same in a tank with only fake plants. Would you? In theory the surface area of a fake plant is the same as a live plant but I've not heard of anyone having luck running a non filtered tank without live plants.

I personally view the purpose of almost any filter as a huge stomping grounds for bacteria. I imagine the majority of the biological filtration is happening in there vs anywhere else in a tank. A nice side effect of a filter is that it can mechanically remove particulate as well (and/or be used a place to store chemical media should you feel the need to do so).
 
#18 ·
For the OP question, if I was changing the substrate of a tank I would approach it as a newly established tank ( with a seeded filter). Check for ammonia and nitrite, check if the cycle is ok and only after I am sure of it add fish slowly.


.....
My point/outlook on it is that biomedia offers far more surface area than anything else in a tank (except when that tank has no formal bio media lol).

I'd be willing to run a planted tank with no filter; but I wouldnt attempt the same in a tank with only fake plants. Would you?
I would and have for years run my tanks with no biomedia as filtration. I remember in the early 90's went in a petshop and all the aquariums had a air-run filter in it. As a child, I had an overstocked aquarium with sand and only a sponge attached to a powerhead. Sponges are not marketed as biomedia but mechanical and have little surface compared to what is claimed for biomedia. No plants, no algae, fish healthy.

Are you really suggesting that 18L of AquaSoil has less bacteria than 1L of Eheim Substrate for example ? AS is porous as well but marketed as a substrate not labeled biomedia...As you say, bacteria do not care about our labels, they will colonize any space where conditions are suitable. On other forums the majority run their planted filter tanks with only mechanical media.

In theory the surface area of a fake plant is the same as a live plant but I've not heard of anyone having luck running a non filtered tank without live plants.
Now you have... innocence taken.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top