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155L Goldfish Cube

goldscapes

Member
Joined
21 Aug 2018
Messages
239
Location
Surrey
So, as requested, here's the progress of my 155L Goldfish Cube in the form of a journal.

This journey started out as an urgent rescue of 2 Goldfish and a Shubunkin from a 54L tank that could no longer cope. I had zero experience of fish keeping when I bought the fish for my daughters on a whim back in February 2016...

Here's what the tank looked like then:
IMG_3203.jpg


Fast forward two years, add another goldfish, loose most of the plants, add some algae and turn that sparkling white gravel to a sludgy brown mess and after loosing a fish and some online research I realised our scaly friends needed a new home and fast!

Online auction sites seemed like the obvious first step and within a couple of days I had a 60cm cube tank with filter and lights.

A trip to the local shop later and here's the new tank on day one (background care of my daughters):
IMG_0729.JPG


Yes, fish in there on day one... I know, I know... but bear in mind I had never even heard of cycling at that point let alone fishless cycling and I thought getting them out of the sludgy mess was better for their short term survival (even now I think this was probably the best option and chance they had).

Despite the advice of the local shop I put way to much sand in there and have been syphoning it out slowly with every water change. I went for a large central island of wood all bound together so I can lift the whole unit out and give the sand a good clean, for anyone that doesn't know goldfish are MESSY and I think my main problem in the old tank was build up of waste in the gravel causing extremely high nitrate levels.

Over the next few weeks, I read a lot of articles on this forum (thanks to everyone here, this really is an invaluable resource) about how to setup a tank and fumbled my way trying my best to keep the critters alive. And I'm glad to say it's now almost 2 months in, the tank has fully cycled and all fish are healthy and as far as I can tell happy in their new home.

Once the tank was stable I added CO2 and a few more (but nowhere near enough) plants.
I repaired a missing cap on the spray bar and moved it to the back wall to improve the flow (which worked wonders).
IMG_0793 2.jpg


A big improvement but still nowhere near enough plants so here's the latest shot following these changes:
  • CO2 moved to an inline diffuser
  • Spray bar fitting adjusted for more surface agitation
  • Anubias and Rosafolia to join the Java Fern and Cryptocoryne
  • Lighting changed to two LED lights and two 15W T8 tubes (these are the only size that fit under the hood)
IMG_0821.jpg


So, where now? Well, I'm still not comfortable that this tank is stable. I'm getting some algae, the lighting is probably not strong enough to justify the use of C02 and there aren't enough fast growing plants in there. I'll add another post shortly with a summary of the tank regime with respect to fertilisers lighting times etc. for anyone that is interested.
 
155L Cube Summary

Filtration
  • 1400 litres per hour
  • two grades of filter sponge and ceramic balls
  • APS Filter extender filled with bioballs acting as a CO2 reactor
Lighting
  • 1x Aqua Glo T8 15w
  • 1x Power Glo T8 15w
  • Both on at the same time for 12hrs
  • Fluval Aquasky
  • 7am-3pm at 25-30%
CO2 & Fertiliser
  • CO2 for 14hrs starting 3 hrs before lights on
  • CO2 Roughly 10 bubbles every 2 seconds (becoming hard to count at this speed)
  • Seachem Flourish, Iron and Potassium weekly as per instructions on bottle
  • TNC Complete 15mm once per week as per bottle instructions
 
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Hi Dave, it’s a good job you’ve done, like the look of the tank, poor little goldfish must be much happier! I’m a total novice but perhaps you’re getting algae due to the 10 hours of lights on. It’s striking how much better a tank looks with more plants in
 
Thank you for your well intentioned suggestion but as a self-confessed total novice I think I might try the Algae section of the forum first :)

That didn’t come out right, makes me sound ungrateful for the advice, which I wasn’t and was sound 👍
 
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And you're right about more plants looking good, the biggest challenge I have had is finding varieties that the goldfish don't munch on. The red plant (Alternanthera Rosaefolia) is taking a bit of a kicking at the moment, in fact if anyone knows of a fast growing temperate plant that won't get eaten I would be extremely grateful to hear about it!

In fact I usually throw in some Cobomba or Elodea to act as a tasty distraction but since I improved the circulation it was getting caught under the hardscape so I took it out, I'll probably get some more and see if it helps.
 
Here's a quick update following today's maintenance, a full tank clean including inflow and outflow tubes.
The water is a little cloudy but much better than before the maintenance, the water had become really dark and I hadn't noticed just how bad it was, now I have a reminder...

IMG_0854.jpg
 
DBFC8664-3810-4409-A3DE-7D589E98F4DC.jpeg
Weekly maintenance complete, just a 40-50% water change some pruning of unhealthy leaves on the ferns and Anubias, and the addition of 2 Bucephalandra Theia and a B. Theia Green to conceal the structural ties and add a bit more plant mass.

The upper leaves of the A. Rosaefolia are looking a bit the worse for wear after I took out the floating plants and the goldfish had nothing else to munch on. Also there is some brown algae on the upper leaves. Lower down there is good new growth but green rather than red leaves. I’m not expecting miracles but maybe nearer the surface the red coloration will return.

Fertiliser ran out so switched to Seachem Flourish and Potassium with some Iron in reserve should I need it.

Finally some floating plants on order so I can try out the “Duckweed Index” approach to fertilising.
 
Updated dosing as per bottle guidelines.
3ml Flourish
5ml Potassium
Twice a week to start with to see how things go from here.
 
Brown algae/slime got worse this week, maybe not consistent enough with the ferts this week? The Roasaefolia, Anubias and Buces all needed a leaf clean. Had to hack back some of the affected rosaefolia that was too delicate to clean :(

Full deep clean of filter, pipe clean (full of sludge) substrate vacuum and glass scrub.

CO2 output must have been effected so will keep an eye on drop checker for the next few days.

Two and a half hour mega clean done! Let’s hope a little more regular fert dosing keeps it at bay.

On the plus side there was some good new growth on the Rosaefolia so let’s hope it continues so the volume and height increases over the coming weeks.

Not going to make any changes to the CO2 setup (reactor etc.) until I can stabilise the tank again.

Floating plant experiment didn’t work, goldfish thought it was watercress...
 
that background though....
also isnt this tank just a tad small for the gold's o_O

Maybe a temporary background for the photos is in order...

As far as the size of the tank goes I think that’s how much water three fully grown goldfish need, they are messy blighters... The Shubunkin alone can grow to 46cm but he’ll be in a pond by then...
 
As far as the size of the tank goes I think that’s how much water three fully grown goldfish need, they are messy blighters... The Shubunkin alone can grow to 46cm but he’ll be in a pond by then...

Excuse me if I'm wrong but I think all three of those are fancy or fantail goldfish, so they'll all get to 6-8" maximum (15-20cm) and may not fair well in English ponds. Some people are successful but it seems rather hit or miss. Traditionally a Shubunkin refers to a single tailed/comet goldfish that grows larger and are very well suited for ponds. Yours looks like a calico fantail to me, big body and double tail. As for the aquarium size, longer and wider would be better but 150l water volume is adequate for now - but when they are larger I'd recommend a better swimming footprint instead of a cube, perhaps around 200l.
 
That’s a relief to hear, our garden would need some serious landscaping to make room for a pond. At the moment there is a strong flow in the tank and they seem more than happy to swim against the current and in and out of the plants so I won’t be rushing to get a new tank, not least because I have no idea where I could fit a longer one in...

Thank you for your input though I will bare this in mind, your words are well received!
 
F8009E46-D9BA-42A6-8DA1-FAD8E0FF3D94.jpeg


Quick addition of some more plants.
3 bunches of Elodea and Limnophilia (I think).
6 Vallisneria Gigantea
4 Water Lettuce
 
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