Water Changes without drop in level

[henryjd]

Hello,
I need to do larger water changes than normal to bring my Nitrates down (currently showing 5.0). In the past I have put a 32 gallon trash can next to the tank, siphoned out 30 gallons and pumped 30 gallons of new salt water back in the tank. during this process the filter is turned off and some of the live rock is exposed.
I am trying to figure out a way to pump out at the same time as adding back, but I am not sure if that will acheive the same results due to mixing.
Ideas?

 

[plawrence5]

I just want to know how you carry a 240lb trash can out to dump it? 8lb x 30gal=240lb
I would think the mixing would counteract.
What kind of substrate are you useing? Sand? Mechanical Filtration?

 

[papagimp]

If you have an overflow running, you can tee off from the line going from the overflow pox into the sump, using ball valves or similar. You shut off flow to the sump and open flow out that tee so as water is being poured in the tank, water will be overflowed into the tee'd off section and into whatever bucket or container you are using to collect old water. It'll mix a bit, the new and old water but as your dumping in new water it'll head to the bottom of the tank, just gravity of you dumping it in, while the water going through the overflow will be from the surface. It'll work fine.

 

[marduc]

First off 5.0 is not that bad for nitrates; however for a 180 gallon 20 to 30 gallons seems appropriate for water changes. How often do you normally do a water change?

Simultaneously removing water while adding it will offset some of the benefit of the change, you want to remove the dirtiest water possible (which is why I blast rocks ect. to free up debris prior to draining) and replace it with the clean. You will be taking 2 steps forward, 1 step back if done the way you are suggesting, however it is still beneficial, just not AS beneficial.

The rock will be just fine with a minimal exposure to air, it happens all the time on reefs when the tide goes out, I wouldn't sweat it, the top of my rock frequently gets exposed during a WC as well, and I notice no adverse effects from this. About the only caveat is if you have sponges on the rock, but chances are any sponge that you may have is lower in the tank or on the underside of rocks in lower light areas anyhow.

 

[henryjd]

Papagimp,
Great idea...sounds like a trip to the plumbing supply store.
And to answer plawrence5's question - I use several spare MAG 12 pumps to move water with 30 feet of clear hose that will reach to the bathroom and kitchen sinks.

 

[wooden_reefer]

The percentage of water actually changed would be very small.

There may be a way but you have to be very careful not to squeeze the corals etc. This is by way of a few large plastic bags, which must be clean without chemical smell.

You drain the old water but you fill a bag a a time in the tank. This would keep the level more or less constant. After you have drained out all the water your want, and filled out all the bags, you then open the bags one at a time.

 

[kkyyllee]

liverock and corals will be fine exposed to the air for a littlw while