I did it at last!! Can I add more fish?

Hi.
I posted about getting a new filter and my new one starting cycling. I have been doing so many water changes everyday since September and I’ve finally got the amonia, nitrite, nitrate and ph perfect! I could throw a party!!

they’ve been fine now for a few days and yesterday I had a day off the water change. All still good!

my aquarium is 300litres stocked with
4 angels
3 filament barbs
4 doplo catfish
1 rummie nose.

when can I add a few more fish? Would today be too soon? It looks so empty!
I’ve seen some lovely rainbows.

thoughts anyone?

Check rainbows against your water and tank figures on seriouslyfish.com

Thank you

Before getting rainbows or anything else, you might want to bump up the schooling numbers of the fish you already have, especially the filament barbs. Barbs are famously nippy if not kept in large enough schools, and I can see them going for your angels fins especially. They really need to be in schools of 8-10 so they spend their time interacting within their own school, rather than turning that aggression outwards onto other community tank members.
Profile on filament barbs, including behaviour and compatibility: https://www.seriouslyfish.com/species/dawkinsia-filamentosa/

Rummynose tetra are also a schooling fish, so your lone fella needs some friends!

You can start adding more fish now, just be aware that right now, the BB colonies have grown to handle your current bioload, so add more fish slowly, like get the rest of the school of barbs, wait for bacteria colony to catch up over a week or so, while monitoring the water for ammonia spikes and nitrites, which might happen since the bioload has increased. Once it's stable again, get the school of rummynose and repeat process, you know? Slow and steady so the bacteria can catch up.

AdoraBelle Dearheart said:

Before getting rainbows or anything else, you might want to bump up the schooling numbers of the fish you already have, especially the filament barbs. Barbs are famously nippy if not kept in large enough schools, and I can see them going for your angels fins especially. They really need to be in schools of 8-10 so they spend their time interacting within their own school, rather than turning that aggression outwards onto other community tank members.
Profile on filament barbs, including behaviour and compatibility: https://www.seriouslyfish.com/species/dawkinsia-filamentosa/

Rummynose tetra are also a schooling fish, so your lone fella needs some friends!

You can start adding more fish now, just be aware that right now, the BB colonies have grown to handle your current bioload, so add more fish slowly, like get the rest of the school of barbs, wait for bacteria colony to catch up over a week or so, while monitoring the water for ammonia spikes and nitrites, which might happen since the bioload has increased. Once it's stable again, get the school of rummynose and repeat process, you know? Slow and steady so the bacteria can catch up.

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Hi, yes I’ve been looking today at all the information and doing a lot of reading on the fish I have. The rummynose I have is the last one out of the original fish I got. I’m scared to add anymore as my angel fish are bigger now and I’m scared they’d eat new ones. I’ve never seen fully grown ones anywhere.
I’m also going to look at rehoming my filament barbs as I don’t think the aquarium is big enough to house a school of filament barbs once they’re full size. It’s a big aquarium but not that big... I'm pretty disappointed in the shop I used that sold me them. They were sold to me as a good fish to go with angels.
I’m away for a few days next week so I’m going to think about my way forward whilst away.

@AdoraBelle Dearheart i have just looked at the link you put on, the filament barbs aren’t as big of a problem as I thought. My aquarium is above the minimum size.
I really need to work it out... I need to stop listening to blooming fish shops advice!

Angb200 said:

Hi, yes I’ve been looking today at all the information and doing a lot of reading on the fish I have. The rummynose I have is the last one out of the original fish I got. I’m scared to add anymore as my angel fish are bigger now and I’m scared they’d eat new ones. I’ve never seen fully grown ones anywhere.
I’m also going to look at rehoming my filament barbs as I don’t think the aquarium is big enough to house a school of filament barbs once they’re full size. It’s a big aquarium but not that big... I'm pretty disappointed in the shop I used that sold me them. They were sold to me as a good fish to go with angels.
I’m away for a few days next week so I’m going to think about my way forward whilst away.

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Ah, if it's the last of a school that you don't want to keep them anymore, that's different and understandable Right now have a single zebra danio left, the last elderly remains of a larger school, and we won't be keeping more zebra danios, so no sense in buying more young ones.

Definitely find a new home for the barbs then, so they don't nip at your other fish. Sorry you were given bad advice, it happens to so many people, so don't beat yourself up. It makes sense when you're new to trust what people in the fish store have to say, they should know. But so many of us learn the hard way that they often give bad advice.

Seriously Fish is written by experts and scientists, and have profiles on most species of fish, it's a great resource to check any fish you plan to get. You can always post questions here too, there's a good chance someone here will have kept whatever species you're thinking of!

Do you know your water GH, pH etc? GH is your water hardness, and can be often be found by checking your local water companies website. Once you know your water hardness, you can select fish that will work with your water, your tank size, and the other fish you have

AdoraBelle Dearheart said:

Definitely find a new home for the barbs then, so they don't nip at your other fish. Sorry you were given bad advice, it happens to so many people, so don't beat yourself up. It makes sense when you're new to trust what people in the fish store have to say, they should know. But so many of us learn the hard way that they often give bad advice.

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Angb200 said:

@AdoraBelle Dearheart i have just looked at the link you put on, the filament barbs aren’t as big of a problem as I thought. My aquarium is above the minimum size.
I really need to work it out... I need to stop listening to blooming fish shops advice!

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Or keep them if they work in your size tank and you like them! They would just be the first school I would bump to 8-10, because of barbs nippy tendencies.

We have very soft water here so I have to add coral sand in every now again (I think that’s what you call it?) to keep the ph at 7ish. I’ve mastered that bit I think..

I spoke to one shop today and they put me off the filaments as I did ask about rainbows too. Surprisingly they had rainbows in stock but no filament barbs. So that’s probably why they advised against it. Luckily I only spoke to them and didn’t go. I knew the filaments need to be in a bigger group that’s why I asked.
We do like the filaments so I think I probably will increase them when I’m back later next week. Then go from there. I do like rainbows, so I think I’ll research those too...

I’ll definitely use the website you posted for information on fish tho as there’s so much conflicting information. ‍

Angb200 said:

We have very soft water here so I have to add coral sand in every now again (I think that’s what you call it?) to keep the ph at 7ish. I’ve mastered that bit I think..

I spoke to one shop today and they put me off the filaments as I did ask about rainbows too. Surprisingly they had rainbows in stock but no filament barbs. So that’s probably why they advised against it. Luckily I only spoke to them and didn’t go. I knew the filaments need to be in a bigger group that’s why I asked.
We do like the filaments so I think I probably will increase them when I’m back later next week. Then go from there. I do like rainbows, so I think I’ll research those too...

I’ll definitely use the website you posted for information on fish tho as there’s so much conflicting information. ‍

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Most rainbows are hard water fish I'm afraid that wouldn't fare well in soft water, I'm sorry. Although if you can find your GH number, what water companies call soft and hard can be a bit different from what fishkeepers call soft and hard, and there might be some species that would work in your range, hard to say without knowing the number.

@essjay knows a great deal about water hardness, I'm basically repeating what she has taught me, because I didn't know about GH and had fish in the wrong water. The coral sand might have affected your GH too, I'm not sure... might need a test kit of your own to check, API do a GH and KH test kit. She's the one to ask about water hardness, and the effects of things like coral sand.

Coral will increase GH slightly but it may well not be enough for rainbows.

Angels, the barbs and the rummy nose are all soft water fish; they do not need the coral sand. You don't say what species of hoplo catfish you have so I don't know if soft water is suitable for them.



Fish have evolved in water with a certain hardness. Soft water fish have evolved to hang on to the few minerals in soft water; put them in hard water and they continue to hand on to the minerals, only there are now so many that they cause deposits in their lidneys and the fish don't live their full lifespan. Hard water fish have evolved to remove most of the minerals in hard water from their bodies; put them in sift water and they continue to excrete the minerals but there are not many in soft water to replace them so they suffer mineral deficiency and get sick more easily.

essjay said:

Coral will increase GH slightly but it may well not be enough for rainbows.

Angels, the barbs and the rummy nose are all soft water fish; they do not need the coral sand. You don't say what species of hoplo catfish you have so I don't know if soft water is suitable for them.



Fish have evolved in water with a certain hardness. Soft water fish have evolved to hang on to the few minerals in soft water; put them in hard water and they continue to hand on to the minerals, only there are now so many that they cause deposits in their lidneys and the fish don't live their full lifespan. Hard water fish have evolved to remove most of the minerals in hard water from their bodies; put them in sift water and they continue to excrete the minerals but there are not many in soft water to replace them so they suffer mineral deficiency and get sick more easily.

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Wow now it’s got complicated. Lol. I have been testing the ph and I’ve managed to keep it at 7 most of/all the time. So is GH different to PH? I’ve been told we have ‘soft’ water by the shops, so that’s where I get that information from. Half way through the cycle my PH dropped to 6.5 but the coral sand brought it back up again. If that makes sense..

GH is not the same as pH. GH is a measure of the amount of calcium, magnesium and some other trace metals; pH is the measure of how acidic or basic water is.

Soft water fish are quite happy at pH below 7.0. You do not need to increase the pH.

Look on your water company's website for hardness. That is a lot more accurate than anything a shop tells you. You need a number and the unit of measurement (there are several they could use).


Soft water often has low KH or carbonate hardness; this buffers the pH against changing. If there is not much KH in the water, the acids produced during cycling can use it all up and with nothing left to buffer the pH, it falls.

And don't worry if all of this seems like a confusing headache, took me a while to wrap my head around it as well! Don't chase the pH, concentrate on the GH. If you can go onto your water companies website and look for a water quality report, that should have the info we need. Look for hardness, the number and units of measurement as essjay said, then she can tell you what that means for your water in terms of fishkeeping, then it's just checking that number against fish profiles, basically

The rest you can learn. It's a steep learning curve when you first start keeping fish! But it gets easier, I promise

I’ve looked on our water boards page and screenshot it. It is as follows. any information on here?