Revamp Opinions 75 Gallon Tank

Greetings, I am preparing to revamp my parents 75 gallon aquarium (about to be my second planted tank) currently housing just one 2.5 inch Common Pleco (Will return if we have to). I am thinking I am going to make a Fantail Goldfish planted Aquarium with 4 of them. However, I need a good stone that won't drastically change the water chemistry. Right now, our tanks use water that is already quite high in PH at 8-8.2 with a KH of 13 and GH of 8 with the help of Equilibrium. However, I really want to use a grey stone for the backbone of the tank as I think Seiryu Stone (heard it can change water) would look sharp against a black background and white sand with, of course, the goldfish. I know, the tank does not look the best, just took out all the artificial decor so it is a barren wasteland for now. I also have a sketch of what I am thinking of doing. I also would use the same ferts and possibly some clippings of plants (suggestions of what to use, I know Goldfish like a good salad) that I used with my other tank which is becoming an underwater jungle! Opinions are greatly appreciated.
PS: I also included a HORRIBLE sketch of what I am thinking so far, hopefully someone can make it out. I will definitely use plenty of Anubias in the rockwork and some Pond Lillies for the back, but other suggestions would be nice.

 

It's probably too small for 4 goldfish especially if you want to add hardscape

 

Sorry, I don't know much about goldfish or cold water plants, but your planted tank is gorgeous. Just wanted to say.

 

what are the background plants? apontegeton?

 

It's probably too small for 4 goldfish especially if you want to add hardscape

Really? I didn't think this would be a problem if the scape is built low and the goldfish are not the single tailed varieties along with plenty of filtration.

Sorry, I don't know much about goldfish or cold water plants, but your planted tank is gorgeous. Just wanted to say.

Thank you! It was really fun to build. I want to do the same for this other tank!

what are the background plants? apontegeton?

If you are talking about the center back plants, yes. They are Apongeton Ulvaceus. However, they were much larger before I gave them a trim.
If anyone knows anything about Seiryu Stone and ph shifts, let me know. Thanks in advance for the help.

 

Really? I didn't think this would be a problem if the scape is built low and the goldfish are not the single tailed varieties along with plenty of filtration.

Thank you! It was really fun to build. I want to do the same for this other tank!

If you are talking about the center back plants, yes. They are Apongeton Ulvaceus. However, they were much larger before I gave them a trim.

All goldfish get pretty big...they can easily grow to 1/4 the entire length of the tank. What you see in petstores are babies

 

Yeah, I am aware that Adult Fantails can get from 6-8 inches. However, their adult size is much smaller than per say a Common Goldfish. Other forums including Fishlore (not Petco or Petsmart, I know they are not trustworthy sources for fish) say you could have a few fantails in a 75 gallon. I do appreciate your imput, not saying I disagree.

 

Yeah, I am aware that Adult Fantails can get from 6-8 inches. However, their adult size is much smaller than per say a Common Goldfish. Other forums including Fishlore (not Petco or Petsmart, I know they are not trustworthy sources for fish) say you could have a few fantails in a 75 gallon. I do appreciate your imput, not saying I disagree.

Well it really comes down to water quality. You can keep fish in anything as long as water is clean but bigger fish = more waste = harder to maintain good water quality.

So I wouldn't say a definite NO to keeping them in 75gal, I just wouldn't recommend it because it'll be quite a consuming task keeping that water clean.

 

I would say yes to the goldfish personally, many people including people on here have said a good general rule is 20 gallons for the first goldfish then an additional 10 gallons for every next goldfish. So for 4 goldfish you would need only 50 gallons, but it is also fine to understock so I think 4 in 75 gals is perfectly fine. This is only for the Fancy goldfish though, not the other kinds.

 

Well it really comes down to water quality. You can keep fish in anything as long as water is clean but bigger fish = more waste = harder to maintain good water quality.

So I wouldn't say a definite NO to keeping them in 75gal, I just wouldn't recommend it because it'll be quite a consuming task keeping that water clean.

Do you think that 2-3 Fantails would be better in this situation? My parents really want to have some Goldfish and they wanted the single tailed varieties and I had to persuade them towards Fantails.

 

Do you think that 2-3 Fantails would be better in this situation? My parents really want to have some Goldfish and they wanted the single tailed varieties and I had to persuade them towards Fantails.

The question I guess is...do you have a plan for dealing with the water quality? Is there a drip system? Is there auto water exchange? How realistically do you think you can keep up water changes? Stuff like that....

Planning ahead is key here because everyone gets lazy once the initial excitement of adding fish dies down

 

The question I guess is...do you have a plan for dealing with the water quality? Is there a drip system? Is there auto water exchange? How realistically do you think you can keep up water changes? Stuff like that....

Planning ahead is key here because everyone gets lazy once the initial excitement of adding fish dies down

I do 35% water changes with my 29 once a week and would most likely do the same or possibly more for the 75 gallon tank. I also constantly monitor my tank with the API Master Kit.

 

Seiryu stone does not affect ph, it is an inert stone (just rinse and give it a scrub in case it has dirt or dust on it).
With good filtration 4 fancies can fit in a 75 gallon without issue. It has a 48x18 footprint which is a lot better than say a 55g or a 20g long (or a 5 gallon for someone's 5 yr old where no one takes care of the fish and it's "only 0.36$"). I would do some thicker sections of stacking for the rocks so the goldfish can hide if they'd like (and giving them more interaction with their environment. Goldfish will eat most plants, a good way to keep them from being as munch happy is to give them leafy veggies and things like squash or broccoli.) Thicker/faster growing plants are going to be easier to keep with goldfish - anubias, ludwigia, anacharis, even aponogeton (while softer leaved it grows pretty quickly).

The good thing is goldfish can handle a crazy amount of ammonia/nitrite/nitrate after they are established -healthy- in the tank (i've seen several threads here and even where I work of goldfish in a smaller tank with over 100 nitrate, some even verging into 300 nitrate, some ammonia and nitrite -sometimes-) so they can live if you skip a water change, just don't do a massive (70% plus) water change after skipping it, smaller back-to-back water changes would be better to avoid shocking the fish.
With a 20-40% weekly water change with four fancies and good filtration (look for about 750-1000gph for giving the tank enough turnover and overall filtration ability) you'd be perfectly fine.

You can even do something like black pvc to give them stable hidey holes to swim through (stack the rock around or even silicone it in place, the pvc can be partially buried for stability and black pvc won't distract like white will). You can use fake plants as a temporary to give you the look of height across the back as the live plants grow in so the fish feel more comfortable in their new home (if you are going planted then adding fish ignore the fake plants part).