Red Devil not laid eggs / DGH and PH help ?

[jimmyNG]

i have 1 red devil female about 7 ~8 " , she is female , because she laid the eggs while i got her 4 months ago,but that moment only her , so after i got another Vieja male almost same size , but 4 months now, they living together is fine, but always Lip locking and tail bashing , and the Vieja will go clean the dish, but the Red Devil not laid the eggs ............ already 4 months since last time laid the eggs,
is it any problem ???
my fish tank is 48 Gal (36 x 18 x 18) / Ph 6.9 ~ 7 .2 / DGH not sure, dont have anything to test...
>> in the tank, only
2 LB Reef Aquarium sand
2 piece DriftWood
temperature 28 C
Rena xp 3 filter
1 dish for lay egg
5 clown loach
1 common pleco

anyone have experience why the red devil not laid eggs again ? and DGH normal is what ? or any suggestion ?
thks for help!!!

[jimmyNG]

no one can help ???
what is Kh and Gh, i only know Ph and Dgh ! any one know why my red drvil not breeding or laid eggs in this 4 months ???

[hondas3000]

you need to do more water change and feed as much as they can eat. Blood worms help a lot as well.