Fish Tank Getting Really Dirty

[Squasedpotato]

Hey guys,

Hope someone can help me out here.

Basically, i'm dealing with a 92 gallon tank, we have five discus and approximately 20 Cardinal Tetra's in there, the tank itself is a Juwel 350 (90G).

Now i know that a sand setup (unless black, obviously) is going to get quite dirty, but this is simply insane! At the moment i'm having to take everything in there out every week and give it a good scrub, all in all it takes two hours every week to get the tank looking back to normal.

At first Algae was a huge problem too, but that's settled down a bit now, the main issue is the dirt, it's not fish crap either, because when i'm siphoning for the weekly water change (25%) it's literally dust particles coming up off the sand.

I should also mention that at the start we only had two discus (don't worry, they wern't on their own for long) and a handful of cardinals but the dirt seems to be the same, it's not increased with more fish like i thought it might.

Juwel recommend changing the white floss on top of the filter pads every week so this is what i've done, i've also tried changing it every few weeks instead since i heard the more clogged up it is the more smaller particles of dust it'll catch but...nope, no luck.

Below i've included before and after pics, before pic is when i've just finished cleaning it, after pic is three days later, believe me when i say it looks even worse in person than it does in the picture lol, the sand is covered with dirt, same with the ornaments, the plants look awful aswell.

Now here's the thing, this isn't my tank (i've just taken responsibility over it), if it was i'd have no problems with getting an external filter to try and fix the problem but it simply isn't an option unfortunately.

Ammonia/Nitrite's are at 0, Nitrate is kept below 15-20.

I'm hoping someone can help me out here, because my feeble mind is having a hard time figuring out why so much dust is appearing in this tank, any help would be much appreciated, thanks!

 

[aqua_chem]

It looks like diatoms to me. If you don't actually have dirt in the substrate, then what you're seeing is probably either diatoms or fish poop accumulation. In either case, filter floss is not going to help you.

 

[Pam is here]

Could it be from leaching from your driftwood?

 

[Rivercats]

With discus you should be doing at least a 50% WC weekly. Many people do two WC's a week. I too think it's diatoms and no matter how often you clean them off they will just come right back until they run their course. One thing that could help, not cure just help, is putting some nerite snails in the tank. They love diatoms along with other algae's and they can't breed in freshwater so you won't get a population explosion. That is the best you can do if there is no filter to work with.

 

[Zimmanski]

Definitely diatoms, I have white sand too and it looks the same as mine, or same as mine did. Definitely change more water and you can try API phos-sorb or seachem has a phosphate remover that will speed things up a bit, that's what I did and it still takes a good bit of waiting but all my tank is almost clear of it.

 

[meloyelo]

I had a big diatom issue in my 75 gallon fresh water tank. I also have sand. Got me 5 little oto cats and within about 4 days they had it all cleaned up. They still keep it in check too. Amazing little fish. I supplement with some zucchini since they keep it so clean. Don't want them going hungry.

 

[Squasedpotato]

Could it be from leaching from your driftwood?

Perhaps, i've took two of the pieces out this week to see if that lessens it at all.

I did already put a Phorax filter medium inside the filter, Juwel claim it removes phosphates etc but it hasn't made a bit of difference, i'll most probably try the API one to see if that helps at all.

Also i've been doing only 25% water changes weekly since the guys at my lfs told me changing the water every week would cause further algae problems as i was reintroducing fresh nutrients in the water on a constant basis which would help the algae thrive, so to only do it every 2-4 weeks.

They do have a point but i was still quite stunned as they knew i had Discus fish in there, so i tried to find a neutral point which was weekly 25% water changes instead of the 50% changes i was originally going to do but it dosn't seem to have helped too much anyway.

I'll see how it goes over the next few days and post back, thanks for the tips folks.