HELP: How to perform Large Water Change

[np73]

Is your display tank too full of live rocks when you said you have tons and tons of them? Maybe you can try bringing some down into your sump and do a bit of rescaping. Your tank maybe too overcrowded and hence reducing water movement and flow which causes dead spots everywhere and these dead spots trap nitrate easily. Try rescaping with your rocks not touching the tank walls at all and put wave makers or pumps behind these rocks for better circulation.

Again when you do all these you may spike up ammonia and nitrate so try housing your fishes onto another tank until your nitrate is close to zero.

Hope these help.

Okay tons and tons of it is just exaggerated (slightly). but i do have lots and lots of LR. Theres this LR formation all the way up to the overflow, and its large enough to house all the inhabitants during lights off. I think the inhabitants favour it because its quite a "dead" zone. there might be one or two dead fish rotting away in there, but the LR mass is really quite huge, so not easy to access to the bottom portion. i have tried wavemakers but they just cant reach the corners/ dead spots in there.

ah ha!

maybe the problem started because once my wavemaker came off its suction cup and ended up blowing directly onto the sandbed creating this huge crater. Think that was 2-3 weeks back. perhaps that caused the ammonia/nitrate spike.

or maybe not.

[np73]

I have bought some rudimentary pipings for the DIY algae scrubber project. i suppose once this is up (and running properly), the PO4 and NO3 levels will come down.

[np73]

I found 2-3 huge bundles of cotton wools in the sump tank. These look like full of detritus (and i suppose high nitrate content). I dumped them away. at the same time yesterday, did another large WC (around 80% this time). Water turned cloudy for next 2-3 hours after WC due to the amount of detritus stirred up in the sump).

End result though is good - water now is in pristine (almost) condition:

pH - 8.2

Ammonia - 0

Nitrite - 0

Nitrate - 20

Phosphate - 0.25

Salinity - 1.023

Finders crossed the days of lousy water is over.

[teebs]

I found 2-3 huge bundles of cotton wools in the sump tank. These look like full of detritus (and i suppose high nitrate content). I dumped them away. at the same time yesterday, did another large WC (around 80% this time). Water turned cloudy for next 2-3 hours after WC due to the amount of detritus stirred up in the sump).

End result though is good - water now is in pristine (almost) condition:

pH - 8.2

Ammonia - 0

Nitrite - 0

Nitrate - 20

Phosphate - 0.25

Salinity - 1.023

Finders crossed the days of lousy water is over.

Since you have found the cause, the days of lousy water should be over...

But just take note that you will still have to vacuum/siphon your sump everytime you do a water change as detritus will make its way there over time.

[babareef]

Well done cos you've found the root of the problem. Now u can add AZNO3 to reduce your nitrate fast to zero. Since you prefer the algae scrubber then go ahead and do it. You might wanna introduce some chaetos in your sump to further reduce the nitrate in the long run. Macroalgae not only good in transporting nutrients and phosphate, they also stabilize your Ph at night and provide oxygen to your display tank.

[np73]

im glad to say this:

Fin rot on both yellow tangs have stopped. The fins are in fact growing back now. The larger one is almost fully recovered, while the smaller one is only recently starting to grow back all the fin parts. They seem to be healing fast now. Just the other day the smaller one was pinched by the boxer shrimp, and the wound recovered within 2 days.

[hockboon]

Well done!

[samfsl]

Glad to hear that your effort has paid off