Algae help please

[Pete2112]

Hi, I'm new to this forum but have been keeping tropical fish for over 15 years, though I'm no expert. For me, my 3 foot tank is a nice think to have in the lounge. I keep small community fish and my tank has a external biological filter which is well matured. I made an effort years ago to have live plants but I didn't do a great job and plants got eaten and looked a mess so I now have plastic plants and plastic rocks etc. These look fine when new, but after a several months they are covered in algae and look awful. I maintain the tank regularly and don't mind cleaning the glass and gravel, doing partial water changes and filter and washing out sections of the canister filter media as recommended in my books always leaving a section so I don't wash away all the beneficial bacteria. The tank runs fine and fish mostly seem to die of old age, and the water stays nicely clear. My only gripe is that the plastic plants and rocks soon look dark green with algae and it is time consuming to clean it off, and it is never a perfect job, and It gets expensive to regularly buy new plastic plants. I'm looking for advice as to whether I need to invest in a UV steriliser to at least cut down on cleaning/replacing plastic plants and rocks. If this might help then any suggestions on makes models wattage etc for my 120 litre tank would be very helpful,.
Thank you.

 

[MattW]

What's the lighting period like? And how much feeding? Excess amounts of anything can be fuel for algae IME. I found out the hard way in one of my tanks. A pic of the tank will help too if possible

 

[Pete2112]

Here's a pic of the tank now. I had a good cleaning and maintenance session the weekend before Christmas. The plants and rocks were painstakingly cleaned, and although it probably doesn't show in the pic, there is still some algae remaining when you look closely.
The tank never gets any direct sunlight and the LED lights are usually on for 6 hours a day, but off when we go out. Feeding is with flake food and kept to a minimum, they are not overfed.
Currently we have 6 rasboras, 8 Cardinal tetras 2 corydoras and 2 small platys that are about the 4th generation that have all bred in the tank.

 

[MattW]

I don't see anything out of the ordinary. Tank isn't over stocked imo, Feeding amount is correct and Lighting period is short. Perhaps a more expiernced member can input their thoughts. As for UV, you could try it out. But for models & products I only know of the Aquael UV filter and the APS UV filter.

Have you tried floating plants at all? Water Lettuce or frogbit love excess nutrients which would reduce food for algae.

 

[Essjay]

UV won't help with algae attached to things. Aquarium UV's have to be enclosed and water passed through the enclosure so algae growing on surfaces is not exposed to UV light.
UV can help somewhat with microscopic algae floating in the water but as not all of it will pass the UV light, it won't get rid of all floating algae.

 

[Pete2112]

Thanks @MattW I've not thought about floating plants but will look into them.
@Essjay I understand that the algae has to pass through the enclosed UV filter. But I had the idea that if I did a very thorough tank clean and replaced all the old plastic plants and rocks with new ones and then put in a good UV filter, maybe this would have a good effect of not allowing any algae to proliferate. Or perhaps this would only stave off the algae accumulation on the plants for a while but eventually return to the same situation.

 

[Colin_T]

Don't waste your money on a UV sterliser or replacement plastic plants. If you want to add live plants that is fine but read below first.

Algae grows anywhere there is water, light and nutrients. In your case you have a light on the tank for 6 hours a day but no live plants in the tank to use the light or nutrients. This means algae has no competition and will thrive in your tank.

There are two ways to fix the problem, either add a heap of live plants to use the light and nutrients, or reduce the light to a few hours in the evening.

Most floating plants are generally easy to grow and will shade the tank and stop the algae from growing. Water sprite, red root floaters, and duckweed all do well in aquariums under artificial light and will normally spread rapidly across the surface.

The following link has basic info on growing aquarium plants and might interest you.

Aquarium Plants 1.01

AQUARIUM PLANTS 1.01 TURNING LIGHTS ON AND OFF Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly. In the morning open the curtains or turn the room light on at...

www.fishforums.net

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The big cream coloured rocks in the tank appear to be limestone. These are made of calcium carbonate and will raise the pH of the water over time. Unless your tap water has a really low pH (below 6.0) the rocks could be pushing it up too high for the fish you have.

I can see harlequin rasboras, a Corydoras, some cardinal or neon tetras, and another fish I can't see clearly. All the fish listed (except the one I can't ID) come from soft water with a pH below 7.0. Depending on what other fish are in the tank and what the pH, GH and KH of your water supply is, you might be better off removing the limestone.

The GH (general hardness), KH (carbonate hardness) and pH of your water supply can usually be obtained from your water supply company's website (Water Analysis Report) or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Angelfish, discus, most tetras, most barbs, Bettas, gouramis, rasbora, Corydoras and small species of suckermouth catfish all occur in soft water (GH below 150ppm) and a pH below 7.0.

Livebearers (guppies, platies, swordtails, mollies), rainbowfish and goldfish occur in medium hard water with a GH around 200-250ppm and a pH above 7.0.

If you have very hard water (GH above 300ppm) then look at African Rift Lake cichlids, or use distilled or reverse osmosis water to reduce the GH and keep fishes from softer water.

 

[Pete2112]

Does anyone on the forum have, or not have, a problem with algae on plastic plants. Maybe I'm doing something wrong. Or perhaps someone knows of an easy clean solution for this.
I remove the plants and rocks, soak them in very hot water for a while and then literally spend hours scrubbing after which they still aren't fully clean. I really hate that part of the fishkeeping maintenance.
The fish are quite happy with the unsightly algae, I tolerate it to a greater extent than my wife, but I don't like my wife nagging me to clean the plants as I hate the job .
No suggestions about changing the wife please

 

[Pete2112]

@Colin_T Thank you, loads of interesting info above and in your link. Seems like there is a fine line to tread dealing with algae, and I have already learned some useful points from my first read of your post. I will have another study on all the above, but my main objective is to reduce the time I spend cleaning to keep the artificial plants and rocks looking good, rather than embark on a detailed study and experimental learning curve. I have other hobbies and interests that take most of my spare time. As I said in my original post, my fish generally seem to have a good long life, possibly helped by my regular maintenance, not overstocking, or overfeeding and by having a biological filtration system that is well up to the task. So although I'm not fastidious about checking water quality etc, I think the tank is working well and continuing to provide a healthy environment for the fish. My rocks must look very realistic in the photo, but they are definitely all plastic or resin, so shouldn't have any effect on the water quality. The big white rock is hollow with thin walls that become slightly bendable when I clean it in hot water. I always have to check for fish hiding inside it before removing it from the tank for cleaning.
So it looks like a UV steriliser might be of limited or no value. Looking at the problem from another angle, is there a non-toxic cleaner I could soak the rocks and plants in that would make the task less onerous, and do a better job than me using a scrubbing brush?

 

[Pete2112]

I just found this thread from earlier in 2024.
Post in thread 'Ornaments n plastic plants' https://www.fishforums.net/threads/ornaments-n-plastic-plants.493639/post-4331778
This guy suggests using hydrogen peroxide. Assuming the plants have a good rinse off before going back in the tank, does anyone see a problem with this?

 

[Colin_T]

You can dunk plastic plants in a bucket of bleach to get rid of algae. Just rinse them well after bleaching.

All you need to do to get rid of the algae in your tank is either reduce light or add live plants. Floating plants are the easiest way to go and some water sprite would fix the problem in a few weeks.

edited to change light plants to live plants

 

[Pete2112]

@Colin_T
Brilliant thanks. Tomorrow I'll be down to my local aquarium shop for some water sprites and floating plants, otherwise I see I can buy them on ebay. Those water sprites should make a nice looking addition to the tank. The plastic plants are looking acceptable right now, but when, or if, they look bad again I'll try bleach and rinse well. I was always skeptical about the chance of any sort of chemicals getting into the tank water, but will make a sure they are well rinsed off.

 

[Lcc86]

Does anyone on the forum have, or not have, a problem with algae on plastic plants. Maybe I'm doing something wrong. Or perhaps someone knows of an easy clean solution for this.
I remove the plants and rocks, soak them in very hot water for a while and then literally spend hours scrubbing after which they still aren't fully clean. I really hate that part of the fishkeeping maintenance.
The fish are quite happy with the unsightly algae, I tolerate it to a greater extent than my wife, but I don't like my wife nagging me to clean the plants as I hate the job .
No suggestions about changing the wife please

I suppose the general consensus is natural is better, but it doesn't work for everyone! I have a small 5 gallon with natural plants but there's one spot where I can't seem to get anything to grow in so I filled it with plastic plants for the timebeing and it's absolutely fine. Floating plants are great though and should multiply quickly, meaning you don't need to go buying more all the time. Water sprite, water lettuce, red root floaters should all help. I agree that we don't all want to spend ages on maintenance, or don't have the time to do so, hopefully the plants will start to do their thing and reduce the need for scrubbing. Plus your fish will like the cover they provide so it's a win win!

 

[Pete2112]

@Lcc86
Thanks, definitely a win win, and those suggestions are cheaper than a UV Steriliser. I do enjoy fishkeeping and find the tank very relaxing to watch, but it is not my main hobby and I just like to keep a nice looking healthy tank in the corner of the lounge, without too much fuss and bother .

 

[Pete2112]

Thanks to everyone for your input on this, and Happy New Year