Restore a Neglected Reef Aquarium


The effects of neglecting a saltwater reef aquarium are not always obvious and will get progressively worse over time. Doing the bare minimum of feeding your fish and maybe adding your two-part solution will suffice short term, but can have some serious long term consequences. 

The decline is often very gradual so it's easy to fall into a rut. While the tank looks fine this week and probably will look alright next week, after 1-2 months have passed you might fail to notice the creeping hair algae or collection of detritus in the sand bed. Once you get used to the sound of your filter sock overflowing, the water sound just becomes commonplace and easier to ignore. Maybe your corals have stopped growing and are simply sustaining or slowly turning brown/losing color. What if your powerheads stop turning and you don't even realize it?

Short of a tank crash where the biological foundation collapses or you experience a dangerous swing in water quality/chemistry that wipes out the entire tank, the degrees of tank neglect can certainly vary and always get progressively worse. That means the longer you wait to turn things around, the harder it is to get cleaned up. 

What Happens to a Neglected Reef Aquarium?

  • Rising nutrient levels
  • Larger swings or variations in critical water parameters
  • The slow decline of fish and coral health
  • Algae and other pests start to proliferate
  • Bacterial imbalances
  • Equipment failure

When the time comes to finally turn your tank around, it is important to be thorough. Cleaning the algae off the glass is great aesthetically but really isn't an immediate threat and does nothing in the way of all of the waste that has collected in your sandbed. Cleaning a powerhead will improve water flow and help stir up detritus but that doesn't matter much if your filter sock is clogged up. Correcting nutrient levels can slow down pest and algae growth but without stable pH and water chemistry, corals are still going to suffer. 

Point is that everything matters and ultimately has an effect on the health of your aquarium so it is equally important to address everything and then maintain a better routine moving forward. 

Perform Water Tests

1. Test Water Parameters

Before making any moves, test all of your water parameters to get an idea of just how off-track things have gotten. Be sure to write down your results and note anything that needs fixing before proceeding. Of course, if something is so far out of range and causing an immediate threat, take steps to correct it. A series of water changes will be part of your clean-up process which will ultimately stabilize the water conditions. 

  • pH
  • Salinity
  • Nitrate
  • Phosphate
  • Ammonia
  • Calcium
  • Alkalinity

2. Attack the Algae

Scrape the glass and clean your rocks as best you can. Remove large growths with tongs or forceps or remove entire rocks for scrubbing outside of the tank, one by one.  This will likely muck up the aquarium water but not to worry, that will get cleaned up with your water change and filter media.  

2. Service The Filtration

Now you need to service your filter and that means removing all of your old nasty mechanical and chemical filter media. Remove filter socks and filter pads, clean any sponges, and dump out your old carbon or GFO. If possible, clean any settled detritus from your filter chambers using a small pump or siphon.  Don't replace any of the filter media with new media just yet, wait until after the water change. 

Clean your aquarium gear

3. Clean Powerheads, Flow Pumps, and Protein Skimmer

Before doing your water change, it's probably a good idea to ensure your pumps are clean and in working order.  Remove and soak your powerheads and return pump in pump cleaner or citric acid. If you foresee an extended period of downtime without pumps moving the water in your tank while you are cleaning things up, just add an air pump with airstone into the display to keep the water oxygenated. 

Clean your protein skimmer collection cup while you're at it; if the skimmer pump needs it, go ahead and soak it in citric acid for cleaning as well. Be sure to also wipe out the skimmer's body and neck to remove any mud that has built up on the inside.  

4. Drain Tank and Perform 20-50% Water Change

While your pumps are soaking, it's a good time to mix up a fresh batch of clean saltwater and get ready for a water change. Get your siphon and gravel vacuum ready and start cleaning the sand while your draining the tank.  If your sand bed is really dirty, only clean a small portion so as not to kick up too much waste in the process. Don't worry, you will do a series of water changes in the following weeks to get your sand bed in tip-top shape. 

You should perform at least a 20% water change but up to 50% is safe. With a neglected tank, the more the better up to about 50% of your tank's total water volume.  It is possible to change out even more but you don't want to risk such a dramatic change in water chemistry for your fish and other aquatics pets. 

5. Rinse Pumps and Fill Your Tank With Clean Saltwater

Once drained, go retrieve your pumps that have been soaking in pump cleaner and give them a good scrubbing to remove build-up.  Rinse thoroughly in RO/DI water and install them back onto your aquarium.  Proceed to fill the tank with clean saltwater.

6. Replace Media and Turn ON The Tank

Now it's time to add new filter socks and a fresh batch of carbon or other chemical filter media.  Get your filtration back in working order and flip on the switch to turn the tank back ON.  Monitor water flow and pump operation to be sure all is working as it should.  Adjust water level accordingly.

Keep your powerheads running strong for at least the first few hours, this will help stir up any detritus that may have settled while cleaning and allow it to be easily removed by your clean filter socks, pads, and sponges. Not a bad idea to manual blow detritus off the rocks and sand bed at this point too, use a bulb syringe to move about the tank blowing detritus out of the rock crevices. 

7. Inspecting Lighting & Other Equipment

After turning on the tank, you should go through all of the rest of your equipment, including the lighting and heater, to ensure proper operation. Be sure the power cords are safely organized and mounted away from moisture and check that any timers are plugged in and working correctly. 

8. Monitor Water Quality and Repeat Water Changes

Perform 20% water changes every 3-5 days for the next few weeks until your tank has stabilized and you are confident things are turning around.  Test water parameters regularly and continue to clean any nuisance algae from the rocks.  You also want to continue cleaning the sand bed with every water change to remove settled detritus. 

9. Restructure Your Maintenance Routine

Obviously, something went wrong the first time around so think about your tank's required maintenance routine.  Commit to the regular water changes and required maintenance or improve the capacity of your tank's filtration. Maybe it's time to invest in an aquarium controller and start automating some of those tasks you just can't stand. From dosing pumps to Auto-water change systems, pretty much anything can be automated these days with the right gear.  You don't want to find yourself back in the same boat next month and sometimes it is just a matter of a few small changes that will make all the difference in terms of being able to keep up with your tank.