Good Numbers Don't Mean A Clean Tank!

...and a clean tank does not mean good numbers

So, I'm doing a Big Clean on my 75 gallon today... Decor scrub, algae scrape, and canister filter cleaning/floss replace. It's been about 18 days since my last water change/vacuum and the algae was getting pretty cozy. It's been a month or two since I cleaned the canister.

I have a big tank with only 2 fancy goldfish, and a very well established cycle. I never see nitrates over 10, my only plant is copious algae I allow to grow on the back wall. My decor is arranged with low spots in the sand that trap most of the mess my ladies make. Except for algae growth on decor it looks pretty clean most of the time.

I decided to post a horrible of my tank water after I scraped the algae and pulled up the decor to show just how messy my tank really is. My sand is sharp black. All that green stuff is mostly fish poo. (My canister isn't doing its job properly which is why I'm cleaning it today) HOWEVER! My tested parameters are 0/0/5 . Wild, huh?

 

...and a clean tank does not mean good numbers

So, I'm doing a Big Clean on my 75 gallon today... Decor scrub, algae scrape, and canister filter cleaning/floss replace. It's been about 18 days since my last water change/vacuum and the algae was getting pretty cozy. It's been a month or two since I cleaned the canister.

I have a big tank with only 2 fancy goldfish, and a very well established cycle. I never see nitrates over 10, my only plant is copious algae I allow to grow on the back wall. My decor is arranged with low spots in the sand that trap most of the mess my ladies make. Except for algae growth on decor it looks pretty clean most of the time.

I decided to post a horrible of my tank water after I scraped the algae and pulled up the decor to show just how messy my tank really is. My sand is sharp black. All that green stuff is mostly fish poo. (My canister isn't doing its job properly which is why I'm cleaning it today) HOWEVER! My tested parameters are 0/0/5 . Wild, huh? View attachment 582413

Because your tank has only been set up for 8 months, you might want to be cautious about scrubbing everything and replacing media at the same time. I see you've got a sponge filter. I'd just thoroughly rinse the sponges in fresh dechlorinated water and reuse them. If the sponges have been running in the tank a few months, it would be safe to replace your canister pads. I wouldn't however, replace any bio media or ceramic rings/ beads- those, and your sponges are where the bulk of your beneficial bacteria (bb) are growing.
I think you probably just need to do a thorough vacuuming every water change, maybe cut back on the amount you feed (algae likes detritus) and maybe rethink your tank light schedule to keep the algae under control better. Goldfish are messy messy roommates! I rinse my canister pads and sponges about every 6 weeks. I have an overstocked 125 gallon cichlid tank and that makes a disaster of my canister pads too!

 

Oh the only thing I'm replacing is the "fine" filter pad on the canister. What I have going on in this tank has all its good bacteria handed down from a tank I started in March of 2018 + some of the original media from this tank, which had been a very long established tropical/discus tank. The algae is a little opportunist because I let it grow as part of my setup. Here's the tank all put together. The entire nice textured background is dark red algae! People think I painted it

 

Oh the only thing I'm replacing is the "fine" filter pad on the canister. What I have going on in this tank has all it's good bacteria handed down from a tank I started in March of 2018 + some of the original media from this tank, which had been a very long established tropical/discus tank. The algae is a little opportunist because I let it grow as part of my setup. Here's the tank all put together. The entire nice textured background is dark red algae! People think I painted it View attachment 582454

What is that cat thing in the back corner? Is that part of a filter intake? It's awesome looking! I like the red algae look. Isn't red algae high in lysine? (Nutrition wise)

 

What is that cat thing in the back corner? Is that part of a filter intake? It's awesome looking! I like the red algae look. Isn't red algae high in lysine? (Nutrition wise)

I dunno if it's high in lysine? I think I have a couple of different kinds colonizing together. I was hoping some more obvious GREEN would move in, and it may yet. The cat thing in the back is actually a cat shaped WINE BOTTLE that I have in front of the intake of my canister filter to downplay the blue prefilter sponge I've got on the end. Haha! Actually, a large portion of the decor in my tank is fish-safe stuff from around my house.

 

I dunno if it's high in lysine? I think I have a couple of different kinds colonizing together. I was hoping some more obvious GREEN would move in, and it may yet. The cat thing in the back is actually a cat shaped WINE BOTTLE that I have in front of the intake of my canister filter to downplay the blue prefilter sponge I've got on the end. Haha! Actually, a large portion of the dacor in my tank is fish-safe stuff from around my house.

Lol! In the picture, it looks like the intake tube is actually plugged into the top of the bottle! Oh and I remember now, red algae is high in Taurine (I had the wrong "ine") lol!