Sun-Mar Spacesaver
#4 in CompostingFull review
For a small cabin bathroom on grid power with one full time user or occasional guests, where a certified toilet is required.
Sun-Mar $1,935$1,935
The Sun-Mar Spacesaver and the BioLet 65 are evenly matched, rated 2.8 and 2.8. The Sun-Mar Spacesaver leads on value. The BioLet 65 wins on capacity. The Sun-Mar Spacesaver costs $1,035 less ($1,935 vs $2,970).
BioLet 65
#5 in CompostingFull review
For full-time households on grid power that want a hands-off composting toilet with no urine bottle; the price and power needs rule it out for vans.
BioLet $2,970$2,970
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Sun-Mar Spacesaver for value ($1,935 vs $2,970).
- Choose the BioLet 65 for capacity (rated for 4 people full-time vs rated for 1 person full-time).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every composting toilet; a clear win is highlighted. How we rank explains each one.
| Factor weight | Sun-Mar Spacesaver | BioLet 65 |
|---|---|---|
| Overall rating | 2.8/5 | 2.8/5 |
| Value 30% | 48 $1,935 | 1 $2,970 |
| Capacity 25% | 0 rated for 1 person full-time | 60 rated for 4 people full-time |
| Power 15% | 8 35 W fan, 160 W heater | 50 power draw not published (neutral score used) |
| Certification 15% | 100 certified to NSF/ANSI 41 | 50 NSF/ANSI 41 certification not stated (neutral score used) |
| Warranty 15% | 50 3-year warranty | 50 3-year warranty |
Specifications
| Sun-Mar Spacesaver | BioLet 65 | |
|---|---|---|
| Capacity | ||
| Type | Composting drum or chamber | Composting drum or chamber |
| Full-time residents | 1 people | 4 people |
| Urine drain option | No | No |
| Agitator | - | Yes |
| Power and venting | ||
| Power | 120V | 120V |
| Fan | 35 W | - |
| Heater | 160 W | - |
| Vent size | 2 in | 2.2 in |
| Build | ||
| NSF/ANSI 41 | Yes | - |
| Dimensions | 19.5 x 23 x 30 in | 26 x 32 x 26 in |
| Weight | 43 lb | 65 lb |
| Material | - | High-density composite |
| Warranty | 3 years | 3 years |