Smell substrate

Redoing my 60l, riversand as a substrate, I noticed that the sand underneath the top layer has gone black/grey, and is smelly. Is this a problem? Is it still safe for my fish, or should I replace the substrate?

Cheers

 

If I were you, I'd replace the substrate.

 

What's causing it though, I don't want it to happen again.

 

It sounds like it could be waste in the substrate. Do you siphon the substrate when you do your water changes? It could be that the old fish food and fish poo and rotting plant leaves getting trapped in the substrate. While usually it's not bad for plants, if it's starting to smell, it's starting to rot. I'd wash it again. and add it back to the tank.

 

Gaawie,

If you have fine organic matter in the medium and if the medium itself is fine then it will use up the oxygen in the gravel to try to decompose the organic matter. Because the medium is so fine, no oxygen can get back into the medium to continue the process, but now the process does not proceed normally and starts using components such as sulphates and other organic substances that are part of proteins to convert them to sulphur or sulphur dioxide. This stuff is toxic to the fishes and to the plants as they need oxygen for their roots to grow. Can you see any healthy roots in the medium, I doubt it. I would throw out the medium, it is too fine, and has too many components in it that can rot. What is this stuff, don't tell me some or other rose compost?

Kind regards,

Dirk

 

Thanks Dirk. It's riversand, it doesn't seem particularly fine... No, there aren't any healthy roots. Eish.

 

Hi Gaawie,

I fear river sand is too fine and if the plants are not putting roots into this medium, then they are telling you that there is this problem.

Why don't you try the palm fibre peat as discussed on my forum, it allows the medium to breathe and really works well. I want to post some pics there of the root growth that I have been getting.

Kind regards,

Dirk

 

I have one question because i fear the same thing happening to me, currently i am using silica sand as my substrate (With added ferts via the water). How deep should the silica sand layer be? What is a safe depth of sand but also deep enough for rooted plants to grow? (I am creating a planted tank).

Thanks
Freaksta

 

Hi Freaksa,

(Name sounds a bit weird and I almost feel that I am insulting you) Which grade of silica sand are you using? Is it the fine stuff, because if it is, it will be OK. The depth does not matter, the deeper it is the less oxygen will penetrate, but that is not bad, because the top layers are the most critical. If this is blocked as it can be with river sand, you have a problem, but filter sand is normally much better.

You must remember that if you only have filter sand as your substrate, it is completely inert, and you are not adding any ferts via the roots. With some plants this is fine and you can feed via the water, but for many plants they do better if they also get ferts via the medium and then filter sand is not enough.

If you are starting off now, check out the palm fibre peat thread to see how you can add this to your substrate. It has major benefits.

Kind regards,

Dirk

 

HI Freaksta

I'm using silica in a few of my tanks and it works great.

What I did was add about 1 cm of organic compost (earth to earth) and then add about 9 cm of pool filter sand on top.

The sand is havy enough to keep the compost down and porus enough to allow good plant growth.

Best of all, it costs next to nothing, and lasts practically forever

 

Hi McClaw,

It is this "organic compost" which is the problem, and it is nothing short of a disaster. I have had numerous inquiries from persons that have had uncontrolled algal growth and neverending disease problems with this sort of substrate. Composts are different in every nursery and they often contain chicken manure, which is a sheer disaster in an aquarium. Chicken manure contains high levels of nitrates which you do not want excess levels of in an aquarium and if it is chicken manure it will contain Salmonella bacteria which will infect fishes and cause bloat and all sorts of other problems.

My advice is therefore to completely steer away from composts, forget about them, use a defined commercial substrate or the palm fiber peat, but DO NOT USE COMPOSTS.

It also does not last forever, composts do not contain a never ending source of nutrients, they have a very limited amount of nutrients which are also not usually the correct onEs and then they are expired.

Diana Walstad recommends composts, but for the modern aquarium, compost belongs in the museum, and causes much more damage than good!

Kind regards,

Dirk

 

Hi Prof

The points you make are VERY Valid.

Any manure will cause serious issues in a tank, not just nitrates, but phosphates also.

This is why I recommended earth to earth organic compost as it contain only plant material.

It also takes longer to break down so it is a more controlled release of nutrients.

Also the nitrients are absorbed by the plants before it goes ito the the water column because of the above and thus you have very little algea growth, the little algea growth I do have is easly controlled by a few apple snails and one or two bristle nose plecos (if it is a big tank).

As every one knows you are DA-MAN when it comes to Plants so I do not want to argue, I'm mainly stating what has worked for me

Regards

Maarten

 

I actually made a mistake with my nick when signing up its ment to be Freaksta, something ive always used online since i was very young.

Thanks a lot for the response, currently i think i can actually do the whole thing as i do not actually have many fish in my tank. I have one chinese algea eater (something the LFS sold me to keep my tank clean haha). 3 Harequins and some baby guppies.

The only problem i do have here in pe is that we have very tight water restrictions at the moment so i will have to drain my 100liters of tank water into something that i can store it in while i do the peat. Maybe i shall do this, this weekend! Just dread the idea of having to take out about 25kgs of silica hehe

Thanks for the advise though. I do have one last question if you dont mind responding, is it best to plant the tank while it has water in it or while it is empty? And if i want to add plants at a later stage once its full of water will the peat not float to the top or should i plant the plant in the silica and the roots will go down into the peat? Again one last thing, you didnt mention how deep the sustrate should be +-.

Thanks
Freaksta

 

Hi Freaksta,

Let is keep to this name then.

My sympathies to you guys in PE, in the north of the country most people are totally G-vol of water, but you guys don't have enough, a typical South African story of the haves and the have nots.......

I would use about 3 cms of palm fibre peat and would cap it with about 2 cm of silica sand, so you do not have to put everything back. Obviously one wants to have a higher gravel level at the back and less in the front, but you can use a bit more at the back in the relative I have indicated in the front.

You must put in the Palm fiber peat and the silica sand without water as the PFP tends to float initially and is very light. It is also better to plant the tank when there is not water in it, but you can also do this when you have filled up the tank. If you want to do this you must leave the tank for a few days after setup before you put in the plants or else some of the PFP will float.

If you are in PE, you should get into contact with Lauré le Roux, who is also on this forum. He grows many plants and I am sure that he could help you as well. You will need ferts and you can send me a PM so that we can perhaps arrange that. Lauré is in the process of organizing a shipment for guys in PE from me.

Kind regards,

Dirk

 

Hi again McClaw,

I am glad that we agree on the compost containing manure, but again the organic compost is a problem as this is different from one source to the next. It is for this reason that I recommend the palm fibre peat. It contains no manure or sand and therefore no bacteria. It contains coconut husk which is uniform and consists chemically of cellulose and lignin, both of which hardly decompose. If you then add Chemicult which contains a balanced mixture of nutrients, then you can control the substrate fed nutrients much better.

It is not correct to think that organic compost releases nutrients slowly and on an ongoing basis, it depends entirely on what it consists of and this can be very variable. Organic compost certainly does not contain enough trace elements and even substances such as nitrates are low, so the value of organic composts is limited. I will agree that they are not as hazardous as chicken manure, but they do not contain enough foods. Although I am not saying that you should immediately change all of your setups, I would like to recommend that you consider the PFP when next you have to start from scratch.

Kind regards,

Dirk

 

Hey freaksa.... when u have enough posts and are able to send pm... Contact Rory. He might be able to change your name for u.

 

Hi Prof

I'll give everyting a try at least once

Once I have bought my farm and have set up some cement dams I'll give this a try.

Regards

McCLaw

 

Thanks will do

 

I have just put my peat and water in a 10L bucket so hopefully everything goes well and ill have it in my tank tomorrow afternoon!