Is a lawnmower blenny and court jester goby too much for a 20 gallon?

[mizimmer90]

I am looking to add a fish or 2 to my 20 gal tank.

Currently have 2 clowns and a YWG. I started to get some GHA and was thinking either a lawnmower blenny or a court jester goby/hectors goby, but I can't decide. Was thinking of just getting both the LMB and one of the gobys (because I like the look of both of these fish) but don't want to overstock the tank. I have a few questions for the reefing hive-mind:

1) Is 5 fish too many in a 20 gal?
2) can a court jester goby and a lawnmower blenny get along well?
3) between the court jester goby and hectors goby, which will eat GHA better? I heard someone mention one is better at cleaning rocks and the other is better at cleaning sand: any truth to this?

 

[MnFish1]

I am looking to add a fish or 2 to my 20 gal tank.

Currently have 2 clowns and a YWG. I started to get some GHA and was thinking either a lawnmower blenny or a court jester goby/hectors goby, but I can't decide. Was thinking of just getting both the LMB and one of the gobys (because I like the look of both of these fish) but don't want to overstock the tank. I have a few questions for the reefing hive-mind:

1) Is 5 fish too many in a 20 gal?
2) can a court jester goby and a lawnmower blenny get along well?
3) between the court jester goby and hectors goby, which will eat GHA better? I heard someone mention one is better at cleaning rocks and the other is better at cleaning sand: any truth to this?

Short answer - it's impossible to know how 2 fish will react. I would say try it

 

[Soren]

I am looking to add a fish or 2 to my 20 gal tank.

Currently have 2 clowns and a YWG. I started to get some GHA and was thinking either a lawnmower blenny or a court jester goby/hectors goby, but I can't decide. Was thinking of just getting both the LMB and one of the gobys (because I like the look of both of these fish) but don't want to overstock the tank. I have a few questions for the reefing hive-mind:

1) Is 5 fish too many in a 20 gal?
2) can a court jester goby and a lawnmower blenny get along well?
3) between the court jester goby and hectors goby, which will eat GHA better? I heard someone mention one is better at cleaning rocks and the other is better at cleaning sand: any truth to this?

I have 2 court jester gobies (Koumansetta rainfordi) in my 30-breeder tank on my desk at work and they do pick at the GHA in my tank while also sifting sand, but not enough to control the algae or keep the sand bed clean. Adding one to your tank is a worthwhile consideration, but I doubt it is a good plan to actually control GHA. I primarily got them because I like them a lot and any utilitarian benefits are additional gain.
I think it would be better for you to consider herbivorous invertebrates and better nutrient export/control/balance to control nuisance algae.

Lawnmower blennies (Salarias fasciatus) will likely grow too large and could get aggressive in a tank as small as 20 gallons from what I have read (no personal experience).

 

[jabberwock]

LMB will likely pick on the YWG. Similar body type and habitat = competition.

 

[jabberwock]

What is the shape of the tank? Cube, peninsula, lagoon? This makes a difference in the community of fish you keep.

 

[vetteguy53081]

I am looking to add a fish or 2 to my 20 gal tank.

Currently have 2 clowns and a YWG. I started to get some GHA and was thinking either a lawnmower blenny or a court jester goby/hectors goby, but I can't decide. Was thinking of just getting both the LMB and one of the gobys (because I like the look of both of these fish) but don't want to overstock the tank. I have a few questions for the reefing hive-mind:

1) Is 5 fish too many in a 20 gal?
2) can a court jester goby and a lawnmower blenny get along well?
3) between the court jester goby and hectors goby, which will eat GHA better? I heard someone mention one is better at cleaning rocks and the other is better at cleaning sand: any truth to this?

You will be fine. Obviously provide good water quality management and diet and control amount fed

 

[Stewchi16]

LMB will likely pick on the YWG. Similar body type and habitat = competition.

Yup. Kills any goby or perching fish for me.

 

[bnord]

get them small and add at the same time - plenty of hiding spots and all will be well - could consider a bi-color instead of lawnmower - and or a shrimp for the goby!!

 

[mizimmer90]

I have 2 court jester gobies (Koumansetta rainfordi) in my 30-breeder tank on my desk at work and they do pick at the GHA in my tank while also sifting sand, but not enough to control the algae or keep the sand bed clean. Adding one to your tank is a worthwhile consideration, but I doubt it is a good plan to actually control GHA. I primarily got them because I like them a lot and any utilitarian benefits are additional gain.
I think it would be better for you to consider herbivorous invertebrates and better nutrient export/control/balance to control nuisance algae.

Lawnmower blennies (Salarias fasciatus) will likely grow too large and could get aggressive in a tank as small as 20 gallons from what I have read (no personal experience).

Thanks for the advice!

I like all these fish for their looks and eating the GHA is a nice bonus! Would be cool if they took care of the issues but I'm happy with them either way

 

[mizimmer90]

What is the shape of the tank? Cube, peninsula, lagoon? This makes a difference in the community of fish you keep.

It's 24" x 14" x 14" so a bit on the longer side for 20 gal. Maybe this will help give some space between them?

The YWG is paired with a pistol shrimp and I never see them lol. Barely ever come out of their hole

 

[mizimmer90]

get them small and add at the same time - plenty of hiding spots and all will be well - could consider a bi-color instead of lawnmower - and or a shrimp for the goby!!

Thanks for the advice!! The YWG is paired with a pistol shrimp and they spend all their time under the rocks lol

 

[i cant think]

It's 24" x 14" x 14" so a bit on the longer side for 20 gal. Maybe this will help give some space between them?

The YWG is paired with a pistol shrimp and I never see them lol. Barely ever come out of their hole

Watchman Gobies are a more aggressive and larger genus (Cryptocentrus). Koumansetta on the other hand is a small and much more peaceful genus of gobies. It’s likely this won’t work out and the already established Cryptocentrus cinctus will become aggressive towards the newly added Koumansetta, potentially risking death due to stress.

Usually I’m not against mixing gobies, but in this size tank with a more aggressive species against a peaceful species being added, it’s unlikely to work out.

The Lawnmower Blenny is a rather weird name to give a blenny. The reason I say this is many don’t eat algae as they are a carnivorous fish as well. This is a species which does well with a carnivorous diet on-top of a herbivorous diet. However, there are some that come in and refuse to eat any carnivorous foods (I’ve found this will lead to malnourishment).

 

[i cant think]

It's 24" x 14" x 14" so a bit on the longer side for 20 gal. Maybe this will help give some space between them?

The YWG is paired with a pistol shrimp and I never see them lol. Barely ever come out of their hole

Watchman Gobies are a more aggressive and larger genus (Cryptocentrus). Koumansetta on the other hand is a small and much more peaceful genus of gobies. It’s likely this won’t work out and the already established Cryptocentrus cinctus will become aggressive towards the newly added Koumansetta, potentially risking death due to stress.

Usually I’m not against mixing gobies, but in this size tank with a more aggressive species against a peaceful species being added, it’s unlikely to work out.

The Lawnmower Blenny is a rather weird name to give a blenny. The reason I say this is many don’t eat algae as they are a carnivorous fish as well. This is a species which does well with a carnivorous diet on-top of a herbivorous diet. However, there are some that come in and refuse to eat any carnivorous foods (I’ve found this will lead to malnourishment).

 

[blaxsun]

I've never had success with any lawnmower blennies on tanks smaller than 30 gallons (I'm not sure if was lack of food source, etc.) It wasn't until I moved up to a 160-gallon that I've been finally able to keep one with their voracious appetites.

 

[mizimmer90]

Watchman Gobies are a more aggressive and larger genus (Cryptocentrus). Koumansetta on the other hand is a small and much more peaceful genus of gobies. It’s likely this won’t work out and the already established Cryptocentrus cinctus will become aggressive towards the newly added Koumansetta, potentially risking death due to stress.

Usually I’m not against mixing gobies, but in this size tank with a more aggressive species against a peaceful species being added, it’s unlikely to work out.

The Lawnmower Blenny is a rather weird name to give a blenny. The reason I say this is many don’t eat algae as they are a carnivorous fish as well. This is a species which does well with a carnivorous diet on-top of a herbivorous diet. However, there are some that come in and refuse to eat any carnivorous foods (I’ve found this will lead to malnourishment).

Thanks for the reply!

I wasn't expecting the YWG would be considered the aggressor! Is this from experience or from reading? From my readings it sounds like the YWG is a peaceful fish. In my experience, my YWG just hangs out in its cave with his buddy pistol shrimp. I rarely even see him come out!

Given that, and that the Koumansetta would occupy different parts of the tank, I'm skeptical that this pairing would be an issue. I'm more concerned with the LMB going after the YWG. Willing to change my mind with the right data though!

 

[mizimmer90]

I've never had success with any lawnmower blennies on tanks smaller than 30 gallons (I'm not sure if was lack of food source, etc.) It wasn't until I moved up to a 160-gallon that I've been finally able to keep one with their voracious appetites.

Good to know! Have you tried supplemental feeding with other algae based foods?

 

[i cant think]

Thanks for the reply!

I wasn't expecting the YWG would be considered the aggressor! Is this from experience or from reading? From my readings it sounds like the YWG is a peaceful fish. In my experience, my YWG just hangs out in its cave with his buddy pistol shrimp. I rarely even see him come out!

Given that, and that the Koumansetta would occupy different parts of the tank, I'm skeptical that this pairing would be an issue. I'm more concerned with the LMB going after the YWG. Willing to change my mind with the right data though!

Actually, this is both personal experience as well as reading. Many of the Cryptocentrus species as they age and start to get large (this genus gets within the 4-5 inch range whilst most other genera get to that 2 inch range at a max). I worked in an LFS and our Watchman’s we got in once they set up a home, they didn’t allow any fish near it.

 

[Stewchi16]

I've never had success with any lawnmower blennies on tanks smaller than 30 gallons (I'm not sure if was lack of food source, etc.) It wasn't until I moved up to a 160-gallon that I've been finally able to keep one with their voracious appetites.

My LMB munches on film algae on rocks but it’s diet is mostly fish flakes and mysis. Won’t touch nori.

 

[blaxsun]

Good to know! Have you tried supplemental feeding with other algae based foods?

Oh yes, everything. I regularly feed both red and green TLF SeaVeggies for the herbivores - the current lawnmower blenny completely ignores it. The same goes for about half a dozen different types of pellets and all types of frozen food.

One of his predecessors would only eat brine and mysis, but he didn't last for more than 3-4 months in the smaller tank.

 

[mizimmer90]

Actually, this is both personal experience as well as reading. Many of the Cryptocentrus species as they age and start to get large (this genus gets within the 4-5 inch range whilst most other genera get to that 2 inch range at a max). I worked in an LFS and our Watchman’s we got in once they set up a home, they didn’t allow any fish near it.

Thank you for sharing this info!