adding rock to my sump

mook1178

Active Member
View Badges
Joined
Dec 27, 2023
Messages
484
Reaction score
540
Location
Lincoln
Rating - 0%
0   0   0
I am thinking about adding 20-30 lbs of rock to my sump for more filtration. My tank is a 75 gal DT with a 40 gal DIY sump. Overall actual water volume is probably around 80-90 gallons.

If I were to add dry rock, I would probably have to watch that my phosphates don't bottom out, correct?
 
OP
OP
mook1178

mook1178

Active Member
View Badges
Joined
Dec 27, 2023
Messages
484
Reaction score
540
Location
Lincoln
Rating - 0%
0   0   0
I understand you both, adding love Rock would be best.

However, that's not an answer to my question. I have plenty of dry rock available to me for free, so I would much rather add the dry rock.

It is from an old system broke down a few years ago. It's been sitting in my buddy's garage and he just wants it gone. I took it all, close to 50 lbs probably. Too much to add all, but I can get a little more than half in the space I have.
 

PPBlimpy

Valuable Member
View Badges
Joined
Jan 9, 2025
Messages
1,690
Reaction score
2,102
Location
Cumberland
Rating - 0%
0   0   0
dry rock will can cause weird spikes. If you already have that rock i would put it in a tub of fresh salt water, small pump and heater and dark cure it for 4 weeks. after two weeks do a water change and add a couple pieces of live rock from your DT to help seed it. At this point it will hopefully taken care of any decay on the rocks and you can rinse in fresh salt water and transfer to your sump.

other options are buying from a local and adding rock that came out of someone elses tank, will help with biodiversity.

or buy from a company that pulls rock from the ocean- probably the best stuff you can put in the tank to help
 

PPBlimpy

Valuable Member
View Badges
Joined
Jan 9, 2025
Messages
1,690
Reaction score
2,102
Location
Cumberland
Rating - 0%
0   0   0
if is pulled from an old system and just let dry it may be best to soak in bleach water first for a cuple days, rinse then dark cure like mentioned above
 

KyleJ42

Well-Known Member
View Badges
Joined
Aug 13, 2020
Messages
616
Reaction score
873
Location
Atlanta, GA
Rating - 0%
0   0   0
Usually not a huge issue depending on your tanks maturity. If you are putting in less dry rock than live rock in it, you SHOULD be alright in theory. I’ve used existing live rock to seed new rock in a tank I wasn’t happy with aquascape-wise, and I didn’t notice any ill effects from it. I’ve just never put more dry rock into a tank than live (In terms of pounds).

Why not cycle it with bacteria in a brute can for a while until it’s live rock and then add it? Wouldn’t cost much since you have the free rock. Could always take a piece of rock from your display to seed in the meantime.

Nothing good in this hobby comes quick or easy, might not be the way you want to do it, but might be the way that gives you better results long term
 

KyleJ42

Well-Known Member
View Badges
Joined
Aug 13, 2020
Messages
616
Reaction score
873
Location
Atlanta, GA
Rating - 0%
0   0   0
Usually not a huge issue depending on your tanks maturity. If you are putting in less dry rock than live rock in it, you SHOULD be alright in theory. I’ve used existing live rock to seed new rock in a tank I wasn’t happy with aquascape-wise, and I didn’t notice any ill effects from it. I’ve just never put more dry rock into a tank than live (In terms of pounds).

Why not cycle it with bacteria in a brute can for a while until it’s live rock and then add it? Wouldn’t cost much since you have the free rock. Could always take a piece of rock from your display to seed in the meantime.

Nothing good in this hobby comes quick or easy, might not be the way you want to do it, but might be the way that gives you better results long term
Also just read your comment about it being from another tank. Thats a little different. I would refer to what was said above. I was referencing NEW dry rock. Good luck!
 

Mr. Mojo Rising

10K Club member
View Badges
Joined
Feb 14, 2021
Messages
13,336
Reaction score
15,812
Location
Toronto
Rating - 0%
0   0   0
I've seen sumps with rocks in them, I think its your choice. Although assuming your tank is fine now, I'm not sure if the added bio filtration would provide any benefit. I would suggest that if you do add them, also add a powerhead as they might become detritus traps.
 

Ziggy17

Valuable Member
View Badges
Joined
Jul 5, 2023
Messages
1,604
Reaction score
1,417
Location
Gotham
Rating - 0%
0   0   0
I understand you both, adding love Rock would be best.

However, that's not an answer to my question. I have plenty of dry rock available to me for free, so I would much rather add the dry rock.

It is from an old system broke down a few years ago. It's been sitting in my buddy's garage and he just wants it gone. I took it all, close to 50 lbs probably. Too much to add all, but I can get a little more than half in the space I have.
As long as he didn’t medicate the tank with copper with that rock in it, I personally don’t see any issues. Perhaps someone can help explain what major problems this could present other than displacing water in the sump for rock.
 

Ziggy17

Valuable Member
View Badges
Joined
Jul 5, 2023
Messages
1,604
Reaction score
1,417
Location
Gotham
Rating - 0%
0   0   0
I've seen sumps with rocks in them, I think it’s your choice. Although assuming your tank is fine now, I'm not sure if the added bio filtration would provide any benefit. I would suggest that if you do add them, also add a powerhead as they might become detritus traps.
100%.

I keep a few small rocks in the sump to seed for when I need to set up my hospital tank, and they absolutely become traps. I have to stir it up around them a lot to keep them from being a sewer, in the sewer.
 

exnisstech

Grumpy old man
View Badges
Joined
Feb 11, 2019
Messages
18,921
Reaction score
30,375
Location
Ashland Ohio
Rating - 0%
0   0   0
Nothing wrong with rock in the sump IME i just don't see any benefit to adding dry rock and it could cause swings. As mentioned I would clean it and seed in a brute with some live rock then add it later.
I've been able to avoid the uglies using all dry rock in the DT but packed the sump full of old live rock.

This is the sump in my 330 that runs as a cryptic zone.
PXL_20240412_153619239.jpg
 
OP
OP
mook1178

mook1178

Active Member
View Badges
Joined
Dec 27, 2023
Messages
484
Reaction score
540
Location
Lincoln
Rating - 0%
0   0   0
Thanks all!

My main concern was phosphate release or absorbtion. I am putting in less rock, probably about 25% of the current amount. I think as stated earlier it should be OK on a phosphate swing. I like the idea of soaking for a month as well to help get rid of anything from the old tank.
 

TOP 10 Trending Threads

WHAT AMOUNT OF LIVE ROCK AND SAND SHOULD BE PRIORITIZED FOR OPTIMAL BIODIVERSITY/FILTRATION?

  • 100% live rock + bagged sand

    Votes: 34 27.0%
  • 100% dry rock + 100% live sand

    Votes: 45 35.7%
  • 50/50 live/dry rock, 50/50 live/bagged sand

    Votes: 27 21.4%
  • 75% live rock, 25% live sand

    Votes: 11 8.7%
  • 25% live rock, 75% live sand

    Votes: 9 7.1%
Back
Top