Diatoms that WONT go away

[pepper169]

Hey guys i’m new to fish keeping, i have 3 cory catfish in a 10 gallon. (i know i need to get more lol) but i have brown algae all over the walls of the tank. i do weekly water changes where i take 75% of the water out and then wipe down the inside of the tank with a wet cloth to get out all the nasty diatoms and replace with new water but recently it has gone all over my gravel and decorations and inside my filter. i read i just have to wait it out and eventually they will all go away but it’s been months and seems to be getting worse. it goes away after my water changes for a few days but comes back again after 3-4 days. all my water parameters are good. nitrates and nitrites are at 0 and ph is at 7. i’m not sure how to get rid of them and it’s really driving me nuts. i have to go out and buy a new cartridge for my filter every week because it just turns brown and gross. can someone please give me advice how to get rid of it or what i’m doing wrong. thank you

 

[Neleono]

Do you have live plants or use fertilizer? Also, what kind of light do you have? How long do you leave your light on each day? Also, if you can, pictures would be appreciated!
Thanks, Nele.

 

[pepper169]

i have no live plants and don’t use fertilizer, my lights are what came with the tank i think they’re led i leave them on for no more then 6 hours a day, sometimes i don’t even turn them on, my tank isn’t by the window or anything, i just cleaned out my tank so they’re not bad at the moment but i’ll upload my filter cartridge and some that i didn’t get off completely. i rinsed out my filter cartridge and i’m going to buy a new one tomorrow

 

[AdoraBelle Dearheart]

Getting new cartridges for the filter all the time is likely the problem, and explains zero nitrates too. You're re-setting the cycle (and costing yourself a bomb!) each time you replace the filter media, extending the time diatoms stick around for. Replace the cartridge with some sponge cut to size, that you can rinse out in old tank water when it needs cleaning - never directly under the tap. Will last you for years, save you a fortune, and let your tank settle down and establish.

Good videos for understanding the nitrogen cycle, and optimising a filter. Don't buy a new cartridge tomorrow!! Buy some sponge, any brand, and cut to size to fit it against the cartridge.

 

[pepper169]

Okay what kind of sponge do you suggest? can i get them from the pet store or do you mean literally any sponge lol and do i just put it in with the filter cartridge or get a whole new filter that uses sponges instead?

 

[AdoraBelle Dearheart]

Okay what kind of sponge do you suggest? can i get them from the pet store or do you mean literally any sponge lol and do i just put it in with the filter cartridge or get a whole new filter that uses sponges instead?

No need to get a new filter, just cut the sponge so you can hold it against the hard part of the cartridge to slot it in and out of filter. That video will explain more clearly! Plus can fill up the extra space in the filter with more sponge = more growing surface for beneficial bacteria.

Get aquarium filter sponge, just because regular kitchen or bathroom sponges can be contaminated with dyes or other chemicals that would harm the tank, but aquarium filter sponges will be safe. Any fish store or pet store with a fish section should have same, and any brand will do since you're cutting it to fit the filter.

 

[AdoraBelle Dearheart]

Also to add - put it in WITH the current cartridge for a few weeks, since the beneficial bacteria needed to process the fish waste will have been growing on that cartridge, and we don't want to throw those away and risk a mini cycle. If it's super gross and gunky, just rinse it in some of the old tank water you've removed after a water change, but better to leave it for 6-8 weeks without rinsing if possible, so the cycle can get established

 

[pepper169]

Okay thank you! i was just thinking because my cartridge is brown i thought maybe when the filter was on it was spreading the diatoms all throughout the tank and that’s why they always came back

 

[raylove]

Yes, blue green diatomic 'algae' can be caused by any parameters that are out of wack. This includes nitrates which, even if you don't keep plants, can actually be too low. Presumably your source water must be zero nitrate otherwise there would be some in your tank too. Therefore the large water changes you are doing are probably making things worse. Try to clean the diatoms away without changing too much water, say 1% per week, particularly with your low fish load.

 

[raylove]

Sorry meant to say 15% not 1%!

 

[Neleono]

Lol by the time I finished writing my reply, everyone already said what I was going to say! I'll just shorten it all up a bit. Try using the trick that Belle sent with the filter cartage to save your cycle. Most stores and fish filter brands that have those replaceable filter cartages are either unknowing of the use of reusable filters, or just want to suck money our of your wallet, unfortunately.

In my experience, the brown colored algae means a possible lack of light. Try to keep the fish light on for 10 hours a day, and keep a schedule so that you turn it on and off at the same time each day. I recommend just buying a light timer. It lets you set how long the light is to be on for and maintains a routine schedule. I of course could be fully wrong with this but even still, I recommend a light timer. They can be bought from most stores like target or Walmart, there are some in pet stores but they are usually more expensive but offer no benefit, or you can order them from amazon. I got mine from target for 5 dollars and it saves a lot of hustle.

Lastly, brown algae is easily removed with a razor scraper. If you don't have one, I recommend getting one but you can always use your finger nails and a towel. Also if you do the thing Belle showed with the video and have some sponge left over, that works well also.

Best of luck, Nele!