Sand Substrate Improvement?

I use root tabs and liquid fertiliser. I use JBL root tabs, or whatever are on sale at the shop at any given time, and TNC lite (nitrate levels in my tap water are very high).
My tanks tend to be low maintenance, and I don't use CO2 either.
There's lots of useful information on Matt's site http://scapeeasy.co.uk/ and I'm sure he'll be able to give you some advice on your planting. 

Root tabs should just need to be placed deep enough to stop them polluting the water... I don't have direct experience with lots of different brands. I bought in bulk so didn't get the opportunity to test out loads of types. Tropica's are very good though expensive. It also used tetra initial sticks which are more reasonable but are more of a long term gentle boost than the plant steroids other brands can be.

I don't recommend liquid co2. It is a very harmful substance used to sterilize surgical instruments. It has not place in a tank, in the long term (i do actually use it during water changes as these add co2 and by using this product then and only then, it prevents algae from taking hold during this time of rapid chanhe in the tank) It is also very ineffective at enhancing plant growth (ive seen 10 times less effective then pressurised co2 mentioned before) and there is a lot of research now to day it does more harm than good. See: https://www.jbl.de/en/blog/detail/123/the-story-of-liquid-co2-fertilisation if interested.

You have clearly had good plant growth in the past, what if anything was different then vs now?

Finally liquid fertilisation. What are your nitrate levels? There are two main types of fertiliser to be concerned with (though there are many more types, I would consider these more specialist). "Micros only" (ensure if you get one if these that is also contains phosphorus), and "complete". Complete also contains nitrogen and potassium. Heavier stocked tanks dont need nitrogen and potassium adding because the stocking itself provides enough.  Most people dont have a potassium tester but we can use nitrates as an indicater.

Consider the plants you want to grow... are they root feeders or water column feeders. If they have extensive root systems they feed more heavily from their roots, of less roots like the hygrophila you mentioned... these are more for anchorage than heavy root feeding.

Lots to go off there... hope I've helped and not confused!

How heavily stocked are you?

It is normally recommended to do a 50% water change each week. Unless you are very lightly stocked I suggest you need to up the volume of water changed pretty quickly.

Of you can advise your stocking level it will also give me a feel for a good fertilisation regime for you.

A shop saying the results are OK is not good enough. They must tell you the numbers. If they don't volunteer the numbers, ask for them.
Too many shops think that low levels of ammonia and nitrite are OK when the only OK levels are zero.
Nitrate must be kept below 20 ppm. It used to be thought that nitrate was OK up to 100 but studies have shown that even 20 ppm is harmful to fish. Again, a shop may think that nitrate over 20 ppm is OK when it isn't (for example it is now known that a high level of nitrate is a major contributor to hole in the head disease)

4 corys, 9 Cardinals, 9 Harlequins, 5 Amano shrimps, 20+ cherry shrimps.

Awesome choices. In what sized tank?

It is normally recommended to do a 50% water change each week.

Hi Matt,

I have asked Sue about this 50% per week recommendation. OK, if you're using the Estimative Index (EI) approach to plant fertilization but otherwise it seems excessive and probably not necessary.

JPC

After I typed the reply in the other thread I discovered that somewhere there is scientific evidence for doing large water changes, but the person who said this didn't give links to any papers. Like Matt, I have found that my fish seem to be healthier with larger water changes.
We do need to remember that it isn't just about keeping nitrate below 20 ppm. In planted tanks, the plants will keep nitrate low so just going by nitrate alone, it would appear that water changes arn't necessary. But nitrate is not the only thing that builds up in a tank. I use to work in a hospital lab and we tested urine for many things. Fish will also excrete similar, if not the same, things as we do - and all the things in urine that we didn't test for. Fish communicate by chemical signals, and these too build up in the water. There are pathogens in all tanks, and water changes combined with cleaning the substrate will remove a lot of these. Minerals in tap water get used up, and water changes replenish these.



I have slow growing plants, with the exception of water sprite as a floating plants. These plants do not need much fertiliser; they get enough nitrogen from the ammonia made by the fish and decaying waste, they get enough phosphorus and potassium from fish food, they get enough CO2 from decaying matter in the tank (fish poo, uneaten food etc). All I use is a trace mineral fertiliser at half dose - I have soft water so my tap water has few minerals.

Is there a way to place better plant growing substrate under the sand, or could I use the tablets?

Hi,

I use Tetra Complete Substrate for the bottom layer of my planted tank substrate and there are many other options. Just be aware that some can leach ammonia into the water. I also use root tabs as, and when, required. TNC Plugs are worth considering. Take a look at:

https://www.practicalfishkeeping.co.uk/gear/review-tnc-plugs-aquarium-substrate-fertiliser/

JPC