What Am I Doing Wrong?

[Scuba Steve]

Once again thanks so much to DaveK for all the information thus far. I hope I am not overstaying my welcome. The more I hear from all the people here the more behind I suspect we are over here in Downunder land. Ok I am becoming more and more confused about what to do.

A brief explanation of what system I am currently using:
800 litre tank including a sump underneath. The tank has a drop off which simply serves to flow the water into the sump. I have about 5 powerheads inside the tank to circulate the water. The substrate i use is marble chips to a depth of about 1 inch. In my sump I have both bio balls and sintered glass (Eheim Substrat pro). Also dacron as a mechanical filter. I also use a UV sterliser, a protein skimmer and periodically carbon and phosphate remover. Oh I also use RO water for top ups and water changes. Ok thats it in a nutshell.

My problems:
High Nitrates (160ppm) Fortunately no ammonia and no nitrites
High phosphate (5+)
Red Algae
Fish suffering from pop eye (prob from high nutrition in water hence nitrates)
Loss of fish
What should I do or change please?
Regards

Steve

[aquaman3680]

The first thing that I would do is remove the bio balls. They can become nitrate factories. What type of skimmer is it? Your loss of fish is probably due to the high nitrates and the algae is due to the phosphates. One thing that I might recommend doing is setting up a refugium for all your excess nitrates and phosphates. What size UV are you running?

Ask as many questions as you want! Thats what this site is for!

Matt

[cheeks69]

How often do you do water changes and what % ? How many fish do you have and how often do you feed ? Which skimmer are you using ? Do you have a refugium with macro algae for nutrient export ? What is the total combined flow from your powerheads and return pump ? Do you use a prefilter so you don't get acumulation of food/detritus in your bio-media ?

I'm not familiar with marble chips but I suspect you get alot of acumulation of detritus and food which will contribute to high nitrate levels, how often do you vaccum it ?

[blue_eyes53813]

Marble chips for substrate? I would get rid of the marbles and use sand. Do you have any live rock? Your filtration for the tank seems off. The bio balls and anything in the filter (like sponges) make tons of nitrates for the tank.

What I would do is replace the substrate with sand, get rid of the filter and get ALOT of live rock, add a refugium with macro algae and make sure the skimmer is skimming good. Keep the Uv sterilizer. Good luck

[Scuba Steve]

Thank you again!
OK consider the bio balls gone :-) It is a Befrlin Red Sea skimmer...the standafrd size I think. A refugium? What and how please? It is an Aqua brand UV rated at 25 watts.

About 20% water changes done fortnightly. I have 10 fish and feed once a day...a minimal amount. Combined powerhead flow is approx. 3500gph and return pump is 1750gph. I use dacron as my prefilter also changed fortnightly. The substrate is vacummed every water change.....fortnightly. One of my thoughts was to plumb the return to undergravel filters to assist in keeping the substrate cleaner.

Kind Regards

Steve.

[sasquatch]

i think you got some great advise above, really if you can move your fish maybe the best thing would be to rebuild? if not maybe cycle some live rock in a pail and when its ready just clean out the display,add new sand and then fix the sump? Steve

[Scuba Steve]

Sand for substate? I have never seen that available over here. I do not have any live rock. Would I put this in the display tank, the sump or the drop off? The only sponge I have is the sheet of dacron as the prefilter. Get rid of the filter? Wow! Really?

Regards

Steve

[cheeks69]

Sand for substate?

Yes a sand bed would be best preferably aragonite based and if deep enough eventually would provide denitrification.

I do not have any live rock. Would I put this in the display tank, the sump or the drop off?

Yes this rock would be placed in the display but you must make sure that it's fully cured otherwise you'll get an ammonia spike and likely would wipe out your fish population. You could also place live rock in your sump if you so choose.

[cheeks69]

A refugium? What and how please?

Building A Refugium - Page 1 - What Is A Refugium? - About Saltwater Aquariums Featured Article by Don Carner

[sasquatch]

You would really find this so much easier, its almost self maintaining and opens so many doors. Steve

[Scuba Steve]

How deep would the sand bed need to be please and where would I get it from?
Does the live rock need to be submerged or just a trickle and does it require light?
Fix the sump?

[saltwaterfarm]

I have seen/heard of sand beds from 2 to 6 inches... Maybe an online vendor or LFS. Carib Sea Aragonite is a good brand to look for.

[Scuba Steve]

I dont mean to sound negative or contradictory but we have always been led to believe over here that sand as a substrate is not good as it eventually becomes a putrid mess or something similar. And the thicker it is the worse it becomes.

Steve

[Dentoid]

The top layer of sand should be stirred or sifted to allow for oxygen and an aerobic layer. This can be accomplished using sand sifting organisms, like star fishes, some gobys, sea cuckumbers and others. Or you can physically stir the surface with a small aquarium rake or when vacuuming the substrate. The bottom layer of sand is the anaerobic (without oxygen) layer that is nasty but harbors the bacteria that breakdown nitrate to harmless nitrogen gas that slowly bubbles out of the system. Thus nitrate reduction. The same thing can be achieved using a 5 gallon bucket filled with sand to within 6-8 inches from the top and have water exiting your tank slowly run over this sand and back into your tank. However, the refugium is the best of both worlds. You can have 4-6 inches of sand and nitrate reducing macro algaes in one place. As well as a place to grow pods, a natural food source, for feeding your tanks inhabitants. Another benefit of the refugium is that you have a place to put organisms that you find in your tank and don't want there.

It's not a bad thing, but like everything else it needs to be maintained.

[murkywaters]

almost sounds like you have a hybrid fresh water/reef tank