Coral chips?

[Awgui]

I had an internal overflow filtration system with different layers of filtration media. First layer was a few layers of the cotton wool, followed by a layer of bio balls, then was layer of coral chips and lastly a layer of grade 1 sand. Each layer is around (2 ft / 3 compartments) = 0.6ft tall and 1.5 x 0.5 ft wide.

Then i see that the forum recommends not to use bio balls and coral chips in filtration systems. So i took the 2 layers out and found that they are actually still debris-free (after 1 year). However, i still completely removed them tihnking that they will convert ammonia too fast to nitrate, leaving the layer of sand inside.

So i am wondering wouldn't the ammonia be converted too slowly then? and ammonia is suposed to be more toxic than nitrate rite?

Will large amount of live rocks be sufficient and i could even take out the last layer of grade 1 sand in my internal filtration box? leaving only 2 packs of carbon and cotton wool on top?

[mUAr_cHEe]

yr experience has proved to be very confusing....

basically.... yr balls and chips are debris free because yr wool doing all the job of mechinal filteration....

yr balls and chips... theortically is there for bacteria to thrive.....

lastly.... layer of grade 1 sand.... how does water filter thru this layer of grade 1 sand????

run thru.... or run over??? that one very important....

a picture pls....

[veliferium]

Huh,you put grade 1 sand into your internal filtration box??

[Awgui]

yup i add them in the very last layer and allow water to flow THROUGH to allow large surface area for aerobic bacteria to grow. Becos i see in the forum that many recommends the taking out of bio balls and choral chips, thus i am following hoping to reduce my nitrate level.

I am pretty confused now, cos actu i am not sure whether to take them out in the ist place. As i saw in one of the threads, it says that high nitrate may be due to high rate of conversion of ammonia to nitrate.

[veliferium]

High nitrate may be low ammonia,low nitrite.

Anyway,do u have a refugium?

[Awgui]

refugium == sump is it? I don't have.