Whats best for growth?

[gex18]

I have a fully functioning discus setup that has been running for 2 years, however due to high discus temps, plants normally turn to mush. Have reordered a lot of plants that are meant to be ideal for discus temps;

Hygro Polysperma
Java fern
Amazon swords
Cyrpt becketti / wendetti
Salvinia
Giant Vallis

I dint want to remove gravel to put laterite / soil down so was wondering if i could 'pot' the plants using laterite as their substrate with a layer of gravel to prevent contamination of water? If any links could you please post them? What substrate is best for plant growth?

Setup / equipment is as follows

Juwel Rio 400 (60" x 18" x 24"high) - 400 litres
Eheim 2329 wet / dry external filter
Ehiem 2018 external filter
Arcadia I-Bar T5 lighting - 2 x 54w bulbs
JBL profi 3 CO2 setup inc ph controller, pressurized bottle. solenoid etc

W/C 2 x 100 litres per week.

Stock
8 x 6" discus
3 x cory julii
2 x Ram cichlids
4 x apisto cacatuoides
2 x golden nugget plecs (L177)
30 cardinal tetras

Cheers guys!

[anti-generic]

gex,
i dont think you need to replace your gravel for plants to grow. especially those plants you mentioned.

try getting some fert tabs like JBL 8 balls or seachem flourish tabs and push them into the gravel near the base of the plants. make sure they dont sit exposed to water. They must be berried.

another thing, are dosing any liquid fertilizers for your plants??

i think the reason your plants arent doing so well is because of your filtration setup. There is just too much filtration and the macro nutrients like nitrates are being eaten up the filter.

ppl correct me if i'm wrong.

Regards,
Eric

[duck]

IMO you need at least 1 more 54W T5.
I don't have a wet a dry filter,I have read that they can cause some CO2 issuse's.
Your substrat is 2 year's old,I would leave it as it is it should be full of goodies for the plants.
You need to feed your plants.
Nitrate is the end of the cycle,What you get coming out of the filter so to speak

[gex18]

The problem i have is i dont want to hack into the juwel hood / tank - was thinking of bolting a powercompact T-5 underneath the i-bar, hoANwever dont want to melt i-bar! Any suggestions?

[gex18]

I have now added the original juwel balalst back into the tankn (2 x 48" 39w tubes) - so the wattage is now 182w rather then 104w - i have also added reflectors and i immeadiatly noticed the difference, the light seems much more intense and directed if you now what i mean. Also what t8 lights do you reccomend for plant growth?