Using sand to rejuvenate old gravel substrate.

[Sarpijk]

Hi all, the other day I read sth really interesting and I would love your input.

My 100 litre dirted tank has been running for about three years. The dirt was capped with small diameter gravel. It is planted mainly with cryptocoryne species.

In the last months I've been having an always present surface film and slow plant growth. Based on the fact I have a lot of river stones I guess there is a lot of detritus present that leads to high organics.

On APC Mrs. Diana Walstad shared another member's advice that a way to rejuvenate old substrates is to add an inch of sand.

The whole idea is that sand will still allow for nutrient exchange but at a slower pace so that inhibits algae growth. Additionally the extra substrate depth is beneficial because it will create both aerobic and anaerobic areas.


Thinking of trying it! What do you think?

 

[Zeus.]

Sand and gravel are both inert substrates so all they provide is anchorage for plants to grow in. Adding a layer of sand or gravel will just cover the existing gravel and detritus and the detritus will still be present.
Surface vacuuming the substrate will remove the top layer of detritus which can be enhanced by using turkey blaster the substrate or deep vacuuming the substrate.
I would at least remove the surface detritus as this will help reduce algae and that what is deep in the substrate accept.
If adding more gravel to create higher areas to enhance you scape is another good reason to add it.
having a low spot in the gravel at front of tank can also be helpful, as when you start seeing detritus in the area it is easy to remove and will help control the rest of the detritus in deeper areas of gravel as to detritus will self level to some some extent.

 

[Sarpijk]

Thanks for the answer Zeus. I should mention that I have already invested in a turkey baster to clean up the substrate. On the other hand Mrs. Walstad advises against this practice on the grounds we are just vacuuming plant "food".

I love the low tech aspect of the hobby and the reason I am thinking of adding the sand is because I seem to have better results and no algae in setups using dirt with sand on top.

Although the Crypts seem to grow well I can't say the same for two lace plant bulbs and my Lagenandra red.

 

[Zeus.]

IMO the detritus is much less of an issue with low tech setups, after all what happens to the detritus in lakes and ponds. With High tech its another story all altogether, hence the weekly 50% WC.