View Full Version : Does anyone have any experience running a large cryptic sump?

03/11/2017, 04:49 PM
Iíve been reading and researching for years about running a cryptic sump and Iíve decided a while back that my next system (the one that Iím getting ready to start building now) will be built around one. To that end, Iíve read a book written by Steve Tyree (CMAT Volume 2) where he goes into approximately 400 pages worth of detail about establishing such a system. Given that many of his corals are legendary, it appears that pretty decent results can be achieved with a system like this.

Iím planning on an approximately 350-400 gallon display and I intend to support that with a 750 gallon filtration tank. The filtration tank will be 8í x 4í by 3í deep and will be arranged as illustrated below:



The filtration tank will house at least 1000 pounds of rock. Iím debating on whether or not I should make the tank 8-12Ē taller and adding a 8-12Ē deep sand bed to the filtration tank. For what itís worth, Iím planning on keeping the display tank bare bottom.

Tyree doesnít make much mention of running an algae refugium in conjunction with a cryptic sump, however it does appear that sponges and other organisms do take in phosphates in their growth. From what I could gather from his book, it appears that an algae refugium is not necessary. However, I intend to add one to my system mainly to increase biodiversity of my system.

I will run my system without a skimmer. From my reading, it appears that skimmers decimate microbial life which, in turn, would have a negative impact on the increased biodiversity Iím striving for in my system. I also intend to go without filter socks.

Additionally, I suppose I could break apart the regions of this larger tank in my design into several smaller tanks, however the interplay between the regions and the transitional zones between the algae area, filter feeder zone, and cryptic area of the tank are important in the overall biodiversity and efficiency of the system as a whole.

Does anyone have any experience or thoughts on running a system like this? Will 750 gallons of filtration tank be enough to support a 350-400 gallon display?

When I get paid in about 3 weeks I plan on beginning construction of my filtration tank. Until then, Iím chomping at the bit to get going on this!

Greg 45
03/11/2017, 06:13 PM
Did you try to contact Steve and ask him for help ??

03/12/2017, 06:39 AM
What are you planning on stocking in your display? I ask because with such a large filtration setup and the type of setup your planning, it will take a long time to really mature and I've seen people who had problems with large sand beds, algae refugium, cryptic zones all connected because they soaked up the nutrients in the bigging and their corals starved. I know you can feed your corals but it's something you might consider.

03/12/2017, 07:54 AM
What are you planning on stocking in your display? I ask because with such a large filtration setup and the type of setup your planning, it will take a long time to really mature and I've seen people who had problems with large sand beds, algae refugium, cryptic zones all connected because they soaked up the nutrients in the bigging and their corals starved. I know you can feed your corals but it's something you might consider.

Yes, I am aware that it will take a while to actually mature. Fortunately I have no money saved up and I can afford to dump about $1,000 $1,500 a month into the project so things will have to go slow. That might sound like a lot of money, but when a I'm looking at requiring at least 4x MP60 powerheads at $600+ a pop and 3 or 4 Kessil AP700 light fixtures at nearly $900 each it'll be a couple of months of saving up money before I can get everything I need to set up the display.

I intent to culture and feed live plankton to the system and feed heavy - which will further add to the bioload (and biodiversity of the system)

As far as stocking the display goes, I'm intending to push the limit on the number of fish in it. However, I'm not really sure what that limit is for a 350 gallon display. In general, I'd like to stick with mostly smaller fish and maybe 3 or 4 medium sized fish (6-8 or so inches in length) and a single big fish (12+ inches). Lots of big fish in aquariums kind of freak me out and I like the movement lots of small fish add.

So, something like:

31-41x Chromis (or more)
11x Ignitus Anthias
2x Tinkeri Butterflyfish
1x Copperband Butterflyfish
1x Clown Tang
2x Ocellaris Clown Fish
2x Six Line Wrasse
3-5x Firefish
1x bicolor blenny
1x dwarf angelfish of some sort
2-4x of dottybacks for pest control
and a handful of other smaller fish

At this point I'm not too concerned with the details of the stocking plan, but this is generally what I'm thinking.

03/12/2017, 08:27 AM
Tyree certainly is a pioneer and desrves a great deal of credit for his contributions! It's fascinating to see research by de Goeij and others give more detail on exactly what sponges are doing. De Goeij shows how sponges are essential to reefs converting the DOC released b y algae and corals into DIC (HCO3) used for photosynthesis by algae and essential for corals to build thier skeletons.

While there is no solid data I know of to say what ratio of cryptic sponges to corals and algae is needed for a healthy reef ecosystem I think your design is more than adequate. And like everything else in our system the extent sponges will grow is more dependant on the food available than the space available. So I think your current design will work fine and since there's lots of cool things that go on in refugiums if you want to go larger and have the space and money I don't see a down side.

As far as intentionally setting up an algae refugium I would not do so. For starters long term use of algae scrubbers have had problems, Delbeek and Sprung discuss this and include the reasoning behind removing the ATS used for the 2.5 million liter coral reef exhibit at ReefHQ at Australia's Great Barrier Marine Park. Research by Kline and Kuntz and by Haas, et al, show that the DOC released by algae are detrimental to corals. But if it's something you really want to do cheato and halimeda produce a lot less DOC compared to other algae especially hair or turf algae.
I would also recommend Forest Rohwer's "Coral Reefs in the Microbial Seas", it's available for Kindle for ~$10.

Additionally, in my experience macro algae growth subsides over time as coral colonies get going and increase in overall mass. Since corals and algae are competing for the same nutrients (organic and inorganic nitrogen and organic and inorganic phosphate) I take this as examples where the corals out compete the algae. Here's three videos of a 500 gallon system I set up and ran for 5 years that had a pretty complex refugium/sump setup but had higher flow rates than endorsed by Tyree. Total water volume in the sump/refugiums was about 1/4 of the DT. You can see as the systme matured the first 8 months or so the nuisance algae dissapaited and after about 14 - 16 months macro algae growth in the lighted refugium pretty much stopped.

03/12/2017, 09:02 AM

Thanks for the recommended readings. I just purchased the book you mentioned and those journal articles should keep me busy for a bit.

I was never aware of the potential detrimental effect of algae refugiums on long-term coral health and you gave me something to consider and research.

I've setup a couple of 30-50 gallon systems in the past, but I never had one established for more than about 2 years as something always seems to come up in my life that forced me to move and tear down my systems right as they begin to mature and coral growth started to take off. It's interesting to see that with little effort your nuisance algae issue pretty much remedied itself.

03/12/2017, 09:25 AM
I've read quite a bit about it and the biodiversity sounds great for a healthy system. What will probably give you the most success is that large amount of rock and water volume not in the display. I do wonder however what will happen with say 5 years of detritus in there. Would hope it will be set up in a way you have a settling area to siphon that out of periodically.

Vinny Kreyling
03/12/2017, 10:25 AM
Just an FYI-- you know those Chromis will eventually dwindle to 1.
Six lines are notoriously nasty & a Clown tang can become a bully.